- New crime scene photographs from the first blast appear to confirm that a pressure cooker was used in the device
- Other photographs submitted to the FBI reveal the scene before and after the second bomb detonated
- Devices were designed to act as 'Claymore' anti-personnel devices - which are meant to maim on the battlefield
- An orange and grey bag can be seen on the opposite side of barriers to spectators before the second blast
- New video shows man in black with shredded pants running away in the aftermath of one of the blasts
- The pressure-cooker bombs were reportedly packed with shards of metal, nails and ball bearings
- Devices are frequently used in Afghanistan, India, Nepal and Pakistan, according to Homeland Security
- Eight-year-old boy, 29-year-old woman and University of Boston grad student killed in the attack
- 183 people injured, at least 23 of them in critical condition and 'a lot' of amputations have been performed
By Daniel Bates In Dorchester, Massachusetts, Lydia Warren and James Nye
PUBLISHED: 18:10 EST, 16 April 2013 | UPDATED: 04:13 EST, 17 April 2013
New crime scene photographs of the remnants of the first bomb which detonated during Monday's Boston marathon appear to show that a pressure cooker was used in at least one of the deadly charges - as experts described the devices as military-style 'anti-personnel' devices.
The exclusive images obtained show the wreckage of a stainless steel pressure cooker with an Underwriters Laboratory safety mark and an imprint that reads gas or electric, with experts describing the devices as military-style 'anti-personnel' devices.
And photographs taken by a member of the public of the second bomb site before and after detonation show an orange and grey bag next to the barrier - right where the bomb appears to have gone off.
Detectives are now investigating the possibility that this bag contained the device that exploded with such devastating effect.
Meanwhile, another photograph from the scene of the terror attacks which killed three people and injured 183 shows a shredded black, padded back-pack or duffel bag that would confirm numerous reports that the bomb was carried in a black bag.
WARNING: GRAPHIC CONTENT AND VIDEO BELOW
Bomb? Photos sent to 7News by a viewer show a bag next to a mailbox by the barricade along the marathon route just before the explosion that left three dead at Boston Marathon on Monday
Shocking: Seconds after the bombs went off on Boylston Street there is no sign of the bag, the picture is blurred because of the graphic nature of the content
Bomb: The photos were produced by the Joint Terrorism Task Force of Boston and provided to Reuters by a U.S. government official who declined to be identified and show pieces of a stainless steel pressure cooker with an Underwriters Laboratory number. One picture shows the imprint: Gas and Electric
The devices are believed to be pressure cooker bombs — a commonplace cooking utensil in many countries — and the device is then detonated using everyday electronic equipment such as digital watches, garage door openers, cellphones or pagers
This picture obtained by Fox 5 Atlanta is believed to be the black back-pack that is thought to have held one of the explosive devices which detonated at the finishing line of the Boston Marathon on Monday
The photographs appeared to confirm that the trigger mechanism of the Boston marathon bombs were indeed battery powered - with experts claiming that they showed a high level of sophistication
This picture reportedly shows the damaged remains of a circuit board - which could indicate how the device was triggered to detonate on Monday at the finishing line of the Boston marathon
Destroyed electronic board parts lie on the ground around the scene of the detonation of the first Boston marathon bomb - in photographs obtained anonymously by Reuters and produced by the FBI
Deadly: Investigators say the bombs used in the Boston Marathon attacks were made from pressure cookers
Furthermore, it is being claimed the deadly devices used in the Boston bombing were designed to act like 'homemade claymores' - powerful, directional anti-personnel devices, sources familiar with the investigation told NBC News.
Described as using a 'low explosive', most likely black powder or smokeless powder, the bombs are reported to have exploded outwards with shrapnel at 3,300 feet per second
While this does not create a more devastating 'blast wave', the Boston bombs had the power to propel metal shards great distances, potentially killing and maiming more - like a military 'claymore' device.
In addition, initial examination of the bombs has revealed they appear to utilize battery packs and circuit boards, which indicates a sophisticated triggering mechanism.
'It appeared to be built from scratch but with a sophisticated triggering mechanism. And frankly, at the end of the day, all bombs are crude devices, and it is the way they are triggered that can be sophisticated,' said one official with strong knowledge of explosives. 'They functioned as designed.'
A law enforcement official told CBS News that the two bombs that exploded were made to look like discarded property. It is still unknown if one or both bombs were in garbage cans. One may have been on the sidewalk.
Earlier in the day, lead FBI agent Richard DesLauriers confirmed that items from the first blast have been recovered and are being sent to a special facility at FBI headquarters in Quantico for study - in the hope that they will lead them to the killer or killers.
He said among those items were 'pieces of black nylon which could be from a backpack and fragments of BBs (ball bearings) and nails possibly contained in a pressure cooker device.
'The bag would have been heavy because of the components believed to be in it. We won't know with certainty until the laboratory completes its final review.'
According to a FBI-Department of
Homeland Security document seen by NBC News, a preliminary examination
of photographs and on-scene reports show that one of the bombs consisted
of a pressure cooker with an as yet undetermined main charge.
The second device was also housed in a metal container says the document, but so far there is not enough evidence to confirm for certain if a pressure cooker was used.
'Someone knows who did this,' added Richard DesLauriers, the special agent in charge of the FBI’s Boston office.
'Importantly, the person who did this is someone’s friend, neighbor, coworker or relative. We are asking anyone who may have heard someone speak about the marathon, or the date of April 15, in any way that indicated that he or she may have targeted this event to call us.'
DesLauriers added: 'At this time, there have been no claims of responsibility.'
Earlier he vowed to go 'to the ends of the earth' to find those responsible.
Last night new photographs submitted to the FBI revealed the scene before and after the second deadly bomb detonated at the finishing line of the Boston marathon - as it emerged that bomb detection units had swept the area twice before the race began.
Visible in the first picture is an orange and grey bag that can be clearly seen on the other side of barriers set up on the sidewalk sitting next to a mailbox as spectators behind cheer on the tired runners.
Investigation: Officials survey the site of a bomb blast on Boylston Street in Boston searching for evidence that might help them find a suspect or suspects
In the second picture, blurred because of the graphic scenes, the bag has disappeared in the aftermath of the bomb detonating to be replaced by a scene of utter carnage.
The viewer who took the pictures and submitted them to 7News in Boston says there may have been an hour or more between the first and second picture being taken.
And in video footage also handed over to the FBI, an unidentified man is seen to flee the scene of one of the blasts as everyone else cowers in the seconds after the explosions.
Dressed all in black, the man's pants have been shredded and he hurriedly looks from left to right before making off in the opposite direction to the where members of the public are aiding the injured.
In a press conference held today, Boston Police Commissioner Ed Davis confirmed that the marathon route had been swept twice by bomb detection units and declared clear.
'[But] people can come and go and bring items in and out" after the races started,' said Davis.
While everyone cowers instinctively, the man dressed in black (highlighted) runs away in the opposite direction to everyone else who was caught up in the blast
As those caught up in the blast appear to help the stricken victims of the bombing - the man in black can be seen to make his way at speed away from the scene
And as the circumstantial evidence builds up around the devastating attacks builds, one counterterrorism expert told said that the Boston bombings bore all the hallmarks of the 2004 Madrid attacks - albeit on a lesser scale.
'This has the hallmarks of a Madrid-style event in many respects,' Rossini told The Daily Beast. 'We don’t know who the bombers are, but I assume it was more than one. It’s just my gut that there might have been two people involved.'
The Madrid commuter train bombings were a coordinated attack that used multiple explosive devices which killed 191 people and wounded 1,800 on March 11th, 2004.
They were attributed to an al-Qaeda affiliated terror cell.
'I’m not sure if it’s domestic, or if there was shrapnel or ball bearings in the bombs,' Rossini said,
'But when I saw a still photo of the explosion, there was what looked like a fireball from an accelerant like a propane tank or gasoline”—yet another similarity to the carnage in Spain.
'Of course, a pipe bomb could have that effect as well.'
Saying that the bomber or bombers most likely dropped the bags easily amongst the commotion during the race, Rossini said that the FBI will be looking to the remnants of the bags to lead them to the killers.
Rossini, however, cautioned against jumping to any conclusions that the bombing was the result of Islamic-inspired terrorism. 'It could be a white supremacist group. We just don’t know.'
People gather for a vigil for the victims on the Boston Common as an investigation continues into dual bombings at the Boston Marathon finish line in Boston, Massachusetts, on Tuesday
A member of the National Guard and a Boston policeman direct a man away from a barricade near the finish line of the Boston Marathon in Boston on Tuesday
People stand during an interfaith prayer service remembering the victims of Boston Marathon bombings at the Paulist Center on Tuesday evening in Boston, Massachusetts
The two bombs that killed three people and injured at least 183 at the Boston Marathon on Monday were made from six-liter pressure cookers crammed with shards of metal, nails and ball bearings and stashed in black backpacks, police sources said today.
The cruelly-designed bombs have 'frequently' been used in Afghanistan, India, Nepal and Pakistan, according to a 2010 Homeland Security Department pamphlet - hinting at the origins of the bombers behind the worst terrorist atrocity in the U.S. since 9/11.
A history of pressure cooker bombs and IEDS since the 1990s: How the crude device popular with al-Qaeda and the Taliban has traveled to the United States
- First reports of pressure cookers being used as bombs date back to the 1990s when Maoist rebels used them during the Nepalese civil war that began in 1996.
- During the early part of the last decade, pressure cooker devices were being used in the creation of IEDs across Afghanistan and Pakistan - and were used with alarming frequency against coalition forces in Afghanistan.
- However, because pressure cookers are not as common in the United States as other developing nations, the Department of Homeland Security issued a 2010 warning to report seeing any in public places unattended.
- The 2010 warning was released several months after the failed May 2010 Times Square bombing - which used one as part of its mechanism.
- In 2011 U.S. Army Private Naser Jason Abdo was charged in plotting to set off a pressure cooker bomb on Fort Hood, Texas
- He reportedly learned how to construct the device from reading al Qaeda's online magazine, Inspire
When the devices exploded near the crowded Boston Marathon finish line around 2.50pm on Monday, victims suffered as many as 40 shrapnel wounds each and at least 10 people needed amputations. Witnesses described seeing body parts flying through the air and shoes that 'still had flesh in them'.
And today, FBI investigators said that they will attempt to reconstruct the deadly bombs that brought havoc to the streets of Boston.
During the day, Federal law enforcement sources have briefed that the two devices were indeed made from pressure cookers and hidden in back-packs.
The recovered pieces suggest that the two bombs were identical and a Boston law enforcement source said that parts of a circuit board were also found - which could have been the method to detonate the devices.
As the evidence strands are brought together, experts have said that despite pressure cooker bombs being used as IEDs by the Taliban and al Qaeda in Afghanistan, it doesn't mean that other people can not discover how to create them.
So far, no one has claimed responsibility and DesLauriers said, 'The range of suspects and motives remains wide open.'
In Washington, Senator Saxby Chambliss, the ranking Republican on the Senate Intelligence Committee, told CNN that the facts point to a domestic, home-grown source.
'There are a lot of things that are surrounding this that would give an indication that it may have been a domestic terrorist, but that just can't be assumed,' Chambliss said.
On Tuesday afternoon, a second victim killed in the blasts was identified as 29-year-old Krystle Campbell, from Arlington, Massachusetts. It comes after another was named as eight-year-old Martin Richard. The third victim has not yet been named - but is believed to be a Chinese graduate student of Boston University.
A Chinese student is confirmed to be the third person killed in the Boston Marathon Bombings. The Chinese Consulate, in New York, is not releasing the students' name at this time
Though the victim has not been named at the request of the woman’s family, she attended Boston University and had gone to watch the marathon with two friends.
The survivor, identified by the consulate as Zhou Danling, is in stable condition at Boston Medical Center.
'She cannot talk now but can communicate with pen and paper,' the consulate said in a statement.
'This is a painful and tragic lesson, but we will learn from this as well,' said Massachusetts Governor Deval Patrick on Tuesday..
also announced that President Barack Obama would attend an interfaith
service honoring the victims of the tragedy at 11 a.m. on Thursday at
Cathedral of the Holy Cross in South Boston.
Collecting evidence: Two men in hazardous materials suits put numbers on the shattered glass and debris as they investigate the scene at the first bombing on Boylston Street
bombs used to kill and maim are believed to have contained black powder
or gunpowder as the explosive, and information on how to make such a
bomb is available on the internet, experts said. The devices were then
left at the scene to look like discarded property, CBS News reported.
Investigators have also found pieces of an electronic circuit board which could indicate a timer was used in the detonation.
Although no group has yet claimed responsibility for the attacks, similar devices were used in the failed 2010 attempt to bomb Times Square by Faisal Shahzad, who admitted he had undergone bomb-making training at a militant Islamist faction camp in Pakistan.
A pressure-cooker bomb is also a preferred weapon of al-Qaeda and listed as the 'most effective' weapon of jihad, according to an English-language terror magazine called Inspire, in an article entitled 'How to Build a Bomb in the Kitchen of Your Mom'.
Another article in Inspire last year listed 'the most important enemy targets' for jihadists in America - and included sporting events, CNSNews noted.
The aim should be to target 'human crowds in order to inflict maximum human losses,' a terrorist known as Abu Musab al-Suri wrote. 'This is very easy since there are numerous such targets such as crowded sports arenas, annual social events, large international exhibitions… etc.'
Bomb: Images from a Homeland Security Department
pamphlet shows a diagram for rudimentary improvised explosive devices
using pressure cookers. Police sources have revealed that the deviced used in the Boston Marathon bombings on Monday used pressure cookers filled with shrapnel and ball bearings
Killed: Eight-year-old Martin Richard from Dorchester, Massachusetts was among the three people killed when two bombs detonated at the Boston Marathon on Monday
Loss: Krystle Campbell, pictured, also lost her
life in the terrorist attack. Doctors originally confused her identity
with a friend, so her parents believed she was alive
If a pressure cooker was used, it probably cost around $100 to construct, say former federal forensic and explosive investigators. It's like a pipe bomb but bigger and more powerful.
Also on Tuesday, Homeland Security Secretary Janet Napolitano said there is no sign the explosions in Boston were part of a 'broader plot,' but her department is still being cautious.
'While there is no current indication to suggest that the events in Boston are indicative of a broader plot.
'Out of an abundance of caution,' she added, 'DHS continues to keep in place enhanced security measures at transportation hubs, utilizing measures both seen and unseen.'
Martin Richard, 8, who was waiting at the finish line with his father, mother and siblings, was among those killed when the two bombs detonated at the crowded sports event. His mother has undergone brain surgery and his six-year-old sister lost a leg. His 12-year-old brother escaped injury.
Neighbors told MailOnline about the moment Martin Richard's father, Bill, returned home still wearing hospital scrubs on Monday night and looking like the 'walking dead' as he struggled to come to terms with his son's death and injuries suffered by his wife, Denise, and daughter, Jane.
In a statement released on Tuesday, he said: 'My dear son Martin has died from injuries sustained in the attack on Boston. My wife and daughter are both recovering from serious injuries.
Device: This image shows a pressure cooker bomb, similar to those that were used in the Boston Marathon attacks on Monday
Blast: Runners continue to run towards the finish line of the Boston Marathon as the first of two explosions erupts near the finish line of the race
Exact Moment: People react as the second explosion goes off near the finish at the Boston Marathon finish line on Monday, sending authorities out on the course
thank our family and friends, those we know and those we have never
met, for their thoughts and prayers. I ask that you continue to pray for
my family as we remember Martin. We also ask for your patience and for
privacy as we work to simultaneously grieve and recover. Thank you.'
Doctors confused another victim, Krystle Campbell, 29, with her friend, so for hours her parents believed she was alive and undergoing surgery. Only when they went to visit her in hospital, did they realize the patient was not their daughter.
Loved: Peace is written on the sidewalk in front of the Richard house in the Dorchester neighborhood of Boston, left, while neighbors embrace in the street
Sympathy: Flowers and gifts are left by loved ones outside of the Richard family home in Dorchester, Massachusetts on Tuesday morning
First pictures: Martin was killed in the first explosion as he waited to give his father a hug at the finishing line. His sister and mother were also injured
Tragic: Martin Richard, right, is pictured with his family. His mother,
Denise, has undergone brain surgery and his six-year-old sister Jane
lost a leg in the blast, while his older brother, Henry, 12, escaped
injury. They are also pictured with his father, Bill
A LOOK INSIDE THE HOSPITALS: HOW ARE THE VICTIMS?
Boston Children's Hospital
8 injuries; 0 critical condition
Ages from 2 to 15 years old
Massachusetts General Hospital
29 injuries; 8 critical condition; 4 amputations
Ages from 28 to 71
Brigham and Women's Hospital
31 injuries; 5 critical condition
Beth Israel Deaconess Medical Center
24 injuries; 4 critical condition; 13 in serious condition
Tufts Medical Center
Boston Medical Center
23 in total; 19 still remain at the hospital
7 critical condition; 6 serious; 6 fair
Please check back for updates
'My daughter was the most lovable girl,' her father, William Campbell Jr. said. 'She helped everybody, and I'm just so shocked right now. We're just devastated. She was a wonderful, wonderful girl. Always willing to lend a hand.'
Another, unnamed victim was also killed in the blasts.
Twenty three of the injured remain in a critical condition and CNN reported that at least 10 victims have needed amputations. At least nine of the wounded are thought to be children, including a two-year-old boy who suffered a head injury.
Another child hurt in the blast was 11-year-old Aaron Hern, of Martinez, California, who was hit by flying shrapnel in his thigh as he waited for his mother to cross the finish line. He is being treated at Boston Children's Hospital and is expected to undergo further surgeries.
Doctors treating the wounded agreed that it appeared the devices had contained sharp metal.
do not know of a motive for the bombings, nor do they have a specific
suspect or anyone in custody. In a desperate move, they have appealed to members of the public to submit photographs and cell phone footage of the marathon and explosions.
Earlier reports noted that officials had arrested a Saudi national, who is being treated for burns and shrapnel wounds, in connection to the bombings after a civilian saw him acting suspiciously at the scene.
But now officials have revealed the man, Abdulrahman Ali Alharbi, 22, is being regarded as a witness, rather than a suspect, the Washington Post reported.
It comes after 20 police and federal officials raided his home on Monday night, but the search turned up nothing.
After the twin detonations ripped through the cheering crowds, one witness told CNN that it 'felt like a huge cannon' and other described horrifying scenes of screaming spectators, missing limbs and unresponsive bodies.
Hunt: Police and federal officials exit an apartment complex at 364 Ocean Avenue with a possible connection to the earlier explosions that occurred during the Boston Marathon on Monday
Sorting through: Bags of people's belongings are sorted near to the Boston Marathon finish line on Tuesday as investigations continue into the bombings
Probe: Officials take crime scene photos a day after two explosions hit the Boston Marathon in Boston, Massachusetts as they try to figure out who was responsible
Paying their respects: People embrace at Boylston Street near the finish line of the marathon on Tuesday morning, a day after the twin blasts
WAS THE TIMING SIGNIFICANT? PATRIOTS' DAY IS REVERED BY RIGHT-WING GROUPS OPPOSED TO THE FEDERAL GOVERNMENT
- Yesterday's attack took place on Patriots' Day, which marks the first battle of the Revolutionary War and the 'shot heard 'round the world.' It is a day held in reverence by right-wing domestic groups and others who oppose the federal government.
- The 1995 bombing of the Oklahoma City federal building, which killed 168, occurred the day after Patriots' Day. Bomber Timothy McVeigh was said believe the date was significant.
- The federal siege of the Branch Dravidian compound, which left 82 members of the cult dead, began on Patriots' Day in 1993.
- Today is also Tax Day, when federal income tax returns are due. In recent years, it has been seized on by members of the Tea Party as cause to protest federal government policies and tax rates.
- A Justice Department source tells MailOnline that authorities are looking into the possibility that the Boston attack, which killed three and injured 183 more at the finish line of the Boston Marathon, could have been planned to coincide with Patriots' Day.
- President Barack Obama himself acknowledged the significance of the holiday during his briefing this afternoon.
- 'Today is Patriots Day,' he said. 'A day that reflects the freedom Boston has celebrated throughout its history.'
'Bodies and body parts. Blood all over,' District Fire Chief Ron Harrington of the Boston Fire Department's District 3 said.
'A little boy lying in the street. A young woman in her twenties. Both dead. It was mayhem. I saw two people with arms hanging loose, and one without a leg. A shoe with flesh still in it.'
At a press conference outside Mass Gen hospital on Tuesday morning, Dr George Velmahos, chief of trauma surgery at the hospital, revealed that eight patients between the ages of 28 and 71 remained in critical condition at the hospital.
Among them four people had undergone amputations, and he said they were still trying to save two legs. Other injuries included wounds from 'pellets, shrapnel, nails', which he believed came from the bombs. Some victims were hit by '10, 30, 40' pieces and most injuries were to the lower extremities.
'The experience is obviously overwhelming,' he said. 'We are all extremely sad. We are suffering emotionally for what happened to the people of Boston and many others. But at the same time, we can't feel but proud because the medical community here in Mass Gen responded in an amazing way.'
He described one doctor who ran the marathon but then, despite being dehydrated, went straight to work, while others jumped on planes to help out.
Doctors at Brigham and Women's Hospital added that they had treated 31 patients from the bomb blasts and that five remain in critical condition.
counter-terrorism sources in the city believed that seven devices were
planted across the city - but only two detonated.
A law-enforcement official said late on Monday evening that investigators believe other packages were simply left behind as runners and pedestrians rushed away from the scene in the aftermath of the blasts.
A federal law enforcement official told CNN that both bombs which detonated at the Boston finish line were small, and initial tests showed no C-4 or other high-grade explosive was used - indicating they were crude devices.
In a press conference on Tuesday morning, Obama reiterated authorities
are still unaware of who was behind the attack - whether it was the work
of an organization or a 'malevolent individual'.
For the first time he acknowledged it was an act of terrorism.
'We will bring them to justice,' he vowed, recounting stories of kindness and heroism following the blasts.
'The American people refuse to be terrorized... If you want to know who we are, who America is, how we respond to evil, that's it: Selflessly, compassionately, not afraid.'
In another press conference on Tuesday, Boston officials said the investigation continues with a 'multitude of resources on the street'.
Special Agent in Charge Richard DesLauriers said there are no known additional threats, while Suffolk County District Attorney Daniel Conley branded the attack 'an act of cowardice'.
An aerial graphic that show how the tragic events of today unfolded at the finish line of the Boston Marathon
Map of the bomb sites in relation to the city and the marathon which was run on Monday
Injured people and debris lie on the sidewalk near the Boston Marathon finish line following an explosion in Boston, Monday, April 15, 2013
Horrific Injuries: Medical workers aid an injured man at the 2013 Boston Marathon who screams out in pain
'We will go to the ends of the Earth to identify the subject or subjects who are responsible for this despicable crime -- and we will do everything we can to bring them to justice,' DesLauriers said.
Commending the efforts of volunteers and emergency responders, Mayor Menino added: 'I've been mayor for 20 years now and I've never seen... people pull together like this. It's a tragedy, but Boston is a resilient city.'
After the twin detonations ripped through the cheering crowds, witnesses described the horror.
The fiery twin blasts took place about 12 seconds and about 100 yards apart, knocking spectators and at least one runner off their feet, shattering windows and sending dense plumes of smoke rising over the street and through the fluttering national flags lining the route.
Blood stained the pavement, and huge shards were missing from window panes as high as three stories.
An injured person is helped on the sidewalk near the Boston Marathon finish line following Monday's two bomb blasts
Looking to heaven: A woman kneels and prays at the scene of the first explosion in Boylston Street as the city comes to terms with the atrocity
The explosions ripped into an idyllic afternoon finish for the marathon. The first men had passed the finish line 2 hours and 10 minutes after the staggered start, and the first women crossed just 16 minutes later.
The first blast sent a quick plume of smoke two stories high. Runners nearby stopped in their tracks, confused and unsure. After a few seconds later, a second explosion happened a half-block away, with a deep boom caught on television cameras.
Emergency personnel rushed to the area, and the street was quickly sealed off.
'I saw it go off and smoke billowed up. Everyone just stopped and hunched down,' said Pam Ledtke, 51, from Indianapolis, who was about 75 yards from the finish line when the explosions went off. 'They didn’t know what to do. All of a sudden, people were screaming.'
doctor, Allan Panter, stood near to the finish line said he
was 25-feet away from the first blast when it detonated.
CELEBRATION TURNED TO TRAGEDY: HOW THE HORROR AT THE BOSTON MARATHON UNFOLDED
9 A.M. - The 2013 Boston Marathon begins.
11:58 A.M. - Rita Jeptoo of Kenya becomes the women's winner, crossing the finish line with a time of 2:26:25.
12:10 P.M. - Men's winner Lelisa Desisa, of Ethiopia, finishes with a time of 2:10:22.
2:50 P.M. - Two blasts go off only seconds apart at the finish line, less than 100 yards from each other on the north side of Boylston Street.
3 P.M. - A fire breaks out in the mechanical room at the JFK Presidential Library, but is reportedly not related to the explosions at the marathon.
3:34 P.M. - The Massachusetts Bay Transportation Authority announces multiple sections of the Green Line will be suspended due to police activity.
4:02 P.M. - The first official reports from the Boston Police Department list two dead and 23 injured.
4:30 P.M. - A third blast goes off near the JFK Library though no one is injured. Authorities say the explosion is being treated as an 'ongoing event.'
4:30 P.M. - Boston Police Commissioner Edward Davis holds a press conference urging people to remain indoors and not congregate in large groups.
5:23 P.M. - The fire in the JFK Library is put out.
6:10 P.M. - President Barack Obama addresses the nation, vowing: 'We'll find out who did this. We'll find out why they did this.'
6:30 P.M. - One of the dead is reported to be an 8-year-old boy.
Walking Wounded: A man staggers away from the scene of the explosions at the 2013 Boston Marathon in Boston
S.W.A.T. team members stand guard on the campus of Massachusetts General Hospital following the marathon bomb blasts on Monday
Boston remained on high alert into Monday night after multiple explosions hit the Boston Marathon finish line area on Patriots Day. At least 140 people were injured and 3 confirmed dead in the explosions.
'I saw at least six to seven people down next to me,' he said. 'They protected me from the blast. One lady expired. One gentleman lost both his (lower) limbs. Most of the injuries were lower extremities.'
Nickilynn Estologa, a nursing student who was volunteering in a block-long medical tent designed to treat fatigued runners, said five to six victims immediately staggered inside. Several were children; one was in his 60s.
'Some were bleeding from the head, they had glass shards in their skin,’ she said.
'One person had the flesh gone from his leg; it was just hanging there.’
Another woman, she added, was lying on a gurney as emergency personnel
raced through the tent, giving her CPR.
Terror: An injured individual near the finish line of the Boston Marathon is rushed away from the scene on a stretcher on Monday
Horrific Scene: The aftermath of the Boston Marathon bombing on Monday evening in the city
A Boston police officer wheels in injured boy down Boylston Street as medical workers carry an injured runner
'I just can’t believe anyone would do something like this,’ Estologa said.
Veteran marathon runner Bill Iffrig, 78, was almost at the finish when 'the shock waves just hit my whole body and my legs just started jittering around.'
Iffrig, can be seen wearing an orange tank top and falling to the ground in video of the explosion, and was helped to his feet by an event volunteer and had just a scratch from his fall, he told CNN.
Right after the blasts, police officers could be seen carrying bloody spectators to medical tents intended for exhausted runners in desperate attempts to save lives.
'They just started bringing people in with no limbs,' said runner Tim Davey of Richmond, Va. He said he and his wife, Lisa, tried to shield their children's eyes from the gruesome scene inside a medical tent that had been set up to care for fatigued runners, but 'they saw a lot.'
President Barack Obama spoke around 6pm Monday evening, saying that the American people stand by those in Boston affected by today's bombing
President Obama talks on the phone in the Oval Office on Monday with FBI Director Robert Mueller and was seated with Lisa Monaco, head of Homeland Security, and Chief of Staff Denis McDonough and was briefed on the attack
The American flag on the East Front of the U.S. Capitol is lowered to half-staff on Capitol Hill, Monday, April 15, 2013, in Washington, to honor the victims of the explosions at the Boston Marathon
'They just kept filling up with more and more casualties,' Lisa Davey said. 'Most everybody was conscious. They were very dazed.'
Authorities in New York and Washington tightened security precautions in the wake of the blasts.
The Bureau of Alcohol, Tobacco, Firearms and Explosives sent all of its bomb technicians, explosives officers, explosives specialists and canine officers from their Boston and New York field divisions to the scene, as well as some investigators from Washington.
The U.S. Federal Bureau of Investigation, Justice Department, Homeland Security Department and other agencies were all lending assistance to the investigation, authorities said.
Obama directed his administration to provide whatever assistance was necessary, the White House said.
Spectators typically line the 26.2 mile race course, with the heaviest crowds near the finish line.
Lucky Escape: Boston Marathon runner Bill Iffrig appears on Piers Morgan on CNN after the marathon explosions on April 15, 2013
Seventy-eight-year-old Bill Iffrig, of Lake Stevens - who fell to the ground in the seconds after the blasts has become one of the unfortunate icons of the Boston marathon bombings
Seventy-eight-year-old Bill Iffrig, of Lake Stevens - is helped from the floor as stewards run to help those affected by the blast - as the second explosion can be seen detonating in the distance
The Boston Marathon has been held on Patriot's Day, the third Monday of April, since 1897. The event, which starts in Hopkinton, Massachusetts and ends in Boston's Copley Square, attracts an estimated half-million spectators and some 20,000 participants every year.
Of the 23,326 runners who started the race on Monday, 17,584 finished before the blast, marathon officials said. The runners were diverted before officials brought the marathon to a halt.
The Boston Marathon released a new statement on Tuesday afternoon, extending its sympathy to families affected by the bomb blasts and thanking all those who helped save lives.
'What was intended to be a day of joy and celebration quickly became a day in which running a marathon was of little importance,' it said.
'Boston is strong. Boston is resilient. Boston is our home. And Boston has made us enormously proud in the past 24 hours... We are committed to continuing that tradition with the running of the 118th Boston Marathon in 2014.'
Action plan: Runners who had not finished the race were stopped before the Massachusetts Avenue overpass
Boston police examine the damage following the massive twin detonations on Monday at the Boston marathon
A man is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013
A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene in a wheelchair
An unidentified Boston Marathon runner leaves the course crying near Copley Square
Have a friend running the marathon? Check out this site to find their most recent checkpoint. Additionally, families looking for loved ones should call 617-635-4500. Anyone with info about explosions should call 1800-494-TIPS
Additional reporting by Sara Nathan.