UPDATE: 10 a.m. Tuesday. Despite rumors that at least seven explosive devices had been discovered at the Boston Marathon scene, no unexploded devices were found by law enforcement, officials said Tuesday morning. And 176 people were in hospitals due to injuries from the blast, 17 of them in critical condition, Boston Police Commissioner Edward Davis said.
"We only have two devices that we are aware of and those were the two that were used in the explosion," Gene Marquez, special agent from the federal Bureau of Alcohol Tobacco, Firearms and Explosives, said during a news conference Tuesday morning.
No suspects have been named, but FBI Special Agent In Charge Rick Deslauriers said all law enforcement agencies involved in the "very active investigation" were speaking with witnesses.
"Our mission is clear to bring to justice those responsible for the Boston Marathon bombing," Deslauriers said. "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 bring them to justice."
Boston Mayor Thomas Menino said, "Boston will overcome."
6 a.m. Tuesday. The number of people injured in the two explosions at the Boston Marathon has climbed to more than 140.
The identity of an 8-year-old boy killed was reported as Martin Richard of Dorchester, Mass., the Boston Globe tweeted. According to the tweets, the young boy had been with his mother and sister to cheer on his father, who was running the race. His mother and sister were being treated for injuries sustained in the blast.
During this year's race, Mile 26 had been dedicated to the victims of the Sandy Hook Elementary School shooting. The Newtown Strong Fund Facebook page posted that all the runners from that team had finished before the blast. CNN has reported that family members of the victims were at the finisher's tent up the road from where the blasts took place on Boylston Street.
NBC has put together a timeline of the event, saying that the two bombs used BB's or ball bearings as shrapnel.
Boston Police and the FBI will be holding a joint press conference with the city at 9:30 a.m. to provide updates.
9 p.m. Monday. An 8-year-old boy was one of three fatalities of the explosions at the Boston Marathon, the Boston Globe and Boston Police reported Monday night. More than 100 people were being treated at Boston's three hospitals.
There was no suspect at Brigham and Women's Hospital, Boston Police Commissioner Edward Davis said at a news conference, but he added that people were being interviewed.
Davis characterized the blast as "very powerful" and said the injuries were very serious. None of the law enforcement officials would comment on the investigation.
The FBI has taken control of the investigation, Massachusetts Gov. Deval Patrick said during the late Monday press conference.
"The city of Boston is open and will be open tomorrow, but it will not be business as usual" as the city recuperates from the shock of the blast, Patrick said.
6:15 p.m. President Barack Obama said there are no Republicans or Democrats today, only Americans and that the federal government would do everything it can to find out what happened at the Boston Marathon on Monday.
"We still do not know who did this or why, and people shouldn't jump to conclusions before we have all the facts," Obama said. "But make no mistake we will find out who did this and we will find out why they did this."
The Boston Marathon is one of the oldest marathons in the country. Run on the state holiday of Patriots' Day, it was also run this year in honor of the victims of the Sandy Hook Elementary School shooting last December.
6 p.m. NBC is reporting that more than 100 people were injured as a result of the blasts at the Boston Marathon finish line.
According to the Boston Police Department Twitter, a fire at the JFK Library was not connected to the two explosions at the marathon finish line around Boylston Street.
"We are still asking people to be calm, to go to their homes and to work closely with us," Boston Police Commissioner Edward Davis said in a press conference.
5 p.m. CNN is reporting 49 people were injured by the blasts.
A third explosion, at the JFK Library at about 4:20 p.m., was confirmed and was being treated as if it was connected to the earlier explosions, Boston Police Commissioner Edward Davis said during a press conference. There were no known injuries in that explosion.
"We want to make sure that we completely stabilize the situation," Davis said. He encouraged anyone with information to contact the department.
When asked whether this was a terrorist attack, the commissioner told reporters to draw their own conclusions given the events.
4 p.m. MSNBC is reporting that the Boston Police say two people have been killed and 23 injured due to the explosion.
The television channel is also reporting that three law enforcement agencies have said a preliminary examination shows that the explosions were caused by a small bomb.
Spectators who witnessed one of the explosions were taken to a department store in Copley Square, where they were reunited with family members who were running. Some runners were taken to another location in Boston because they could not leave the city. They were told there was a possibility that there were other bombs around the city that had not exploded.
BOSTON - Only hours after winners were announced, two explosions occurred at the finish line of the Boston Marathon, according to the Boston Herald.
According to the Boston Herald, at least a dozen people were injured.
Norwalk’s Jim Gerweck was at the race working in the press room when the explosions occurred. “We heard two booms in the press room five seconds apart,’’ Gerweck said. “A few minutes later were told of reports of bombs and the press room was locked down. We only know what is coming off of the TV.”
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