Two explosions rocked the finish line of the Boston Marathon this afternoon, leaving at least 2 dead and 23 injured, the Boston Police Department reports.
The explosions happened in quick succession four hours after the beginning of the men's race. At that point, the majority of runners had crossed the finish line. Thousands, however, were still out on the course.
WGBH's Anne Mostue tells our Newscast unit she heard two very loud explosions within seconds of each other. Mostue said immediately after, she saw "people screaming and running toward the river."
"Police [were] pushing everyone away from Copley square," WBUR's Bruce Gellerman said. "People crying, people sitting collecting their thoughts. Some of the runners still shaking."
A video feed of the marathon finish line showed empty stands and emergency workers on the scene. Images posted on twitter and taken by wire photographers showed bloodied runners lining the streets, the windows of nearby buildings blown out by the explosion.
The cause of the explosion has not been determined. But the AP reports that security has been beefed up in New York and Washington.
Update at 4:57 p.m. ET. Third Explosion:
Boston Police Commissioner Edward F. Davis said during a televised news briefing that a third explosion happend at the JFK Library.
"We believe it's related," Davis said.
The JFK Library said the fire at the building has been put out and that investigators are investigating. The Library said "all staff and visitors are accounted for and safe."
Davis asked everyone in Boston to stay indoors and avoid congregating in large groups.
He was asked if this was a terrorist attack.
"We're not being definitive," he said. "You can reach your own conclusions."
Update at 4:50 p.m. ET. The Explosion:
The Boston Globe just posted video of the moment of the explosions. You can hear the first explosion, closely followed by a second one. Then you can hear, someone scream, "We need help," as authorities start removing the barriers to help the victims.
Update at 4:12 p.m. ET. One Explosion Followed By Another:
NPR's Peter Sagal tells All Things Considered that he had just finished the marathon, when he heard an explosion. He said he turned his head and that's when the second explosion hit.
He said he was about 100 yards from the explosion and emergency personelle immediately descended on the scene.
Update at 4:09 p.m. ET. At Least 2 Dead:
The Boston Police Department reports on twitter that at least 2 people are dead and 23 people have been injured.
Update at 3:58 p.m. ET. Counter Terrorism Officials On The Scene:
NPR's Dina Temple Raston reports that the FBI has sent counter terrorism officials to the scene.
The White House says that President Obama has been notified of the incident and his administration is in contact with law enforcement authorities.
"He directed his administration to provide whatever assistance is necessary in the investigation and response," a White House official said.
Update at 3:46 p.m. ET. The Extent Of Injury:
WBUR is reporting that "at least a dozen are injured." CNN is reporting that at least 6 have been injured.
"Police pushing everyone away from Copley square. People crying, people sitting collecting their thoughts. Some of the runners still shaking," Bruce Gellerman reported.
A video of the explosion shows the official marathon clock hitting 4:09 as the explosion happens. The explosion is so severe, one runner is thrown off his feet.
At four hours, most runners would have already crossed the finish line.
Update at 3:35 p.m. ET. Live Coverage:
WBUR is streaming its live coverage here. The New England Cable News is streaming its live coverage here. The Boston Globe is live blogging.
Update at 3:29 p.m. ET. 'Horrific':
The New England Cable News' Jackie Bruno tweeted that she was close enough to the blast that she felt the force of the explosion.
"Runners were coming in and saw unspeakable horror," Bruno tweeted. She also posted a photograph people tending to the injured. It shows one man lying on the ground, blood all over his legs.
Update at 3:22 p.m. ET. 'It Was Awful':
Aaron Michael, a witness tells WGBH that he looked outside when after the first explosion. That's when he heard the second one. :
"Boom, there was black smoke," he said. "Mass chaos. I saw one woman really, really badly hurt. She was being carried out by people, she was bleeding pretty badly. It wasn't a good scene. It was awful."
Update at 3:20 p.m. ET. Oldest Marathon:
As Mark reported earlier, The Boston Marathon is the oldest, most prestigious marathon in the world. Tens of thousands of runners participate in the race.