Throughout the day, we'll be updating with the latest news about the two explosions Monday near the finish line of the Boston Marathon. The blasts killed at least three people — one of them an 8-year-old boy — and injured about 180. We'll also be publishing related posts as the day continues. (See this note about how we cover events such as this.)
8:50 a.m. ET. Where Things Stand.
INVESTIGATION: FBI Special Agent in Charge Richard DesLauriers said Tuesday that investigators have recovered pieces of one bomb. DesLauriers said "BBs and nails," which may have been inside a pressure-cooker style bomb, have been sent to Quantico, Va. for analysis. On Wednesday, Massachusetts Gov. Deval Patrick (D) cautioned that it will be a "long, painstaking investigation."
NPR's Dina Temple-Raston reports that an official familiar with the investigation told her the bomb was "a pressure cooker design with nails and ball bearings inside." And Dina said on Morning Edition Wednesday that FBI investigators think the key clue to finding who's responsible may come from a photo or video taken by a spectator — evidence that "people don't know is important, but the FBI looks at and sees some clue." At the website of the FBI's Boston Division, officials have posted this appeal for help: "If you have any information that could be of assistance, please call 1-800-CALL-FBI (prompt #3). No detail is too small."
President Obama told reporters Tuesday that it's clear this was an "act of terrorism," but that it's not known yet whether it was the act of an individual or a group, and whether it was foreign- or domestic-related.
Also on Morning Edition, NPR's Tom Gjelten reported about "soft targets" such as marathons and the steps authorities take to protect them.
DEATHS, INJURIES: Two of the three people who were killed have been identified: Martin Richard was 8 years old and Krystle Campbell was 29. A third victim is reported to be a Chinese citizen who was studying at Boston University. The school says "the student's name has not been released, pending permission to do so from the family. The student was one of three friends who watched the race near the finish line. Another of the three students, also a BU grad student, was injured."
Around 180 people were injured. As of Wednesday, among those being treated at Boston Medical Center just two remained in "critical condition." CNN was reporting that about 100 people had been allowed to go home. Related post on the Shots blog: "Boston Doctors Compare Marathon Bomb Injuries To War Wounds."
Most of the 10 or 11 victims being treated at Boston Medical Center who were initially in critical condition have made good progress, chief trauma surgeon Dr. Peter Burke just told reporters. He said just two patients remain in critical condition, and that he expects them to survive their injuries. Burke added that 10 patients at the hospital are now considered to be in "serious" condition. Another seven are said to be in "fair" condition.
No "specific suspect or targets" have yet been identified, Massachusetts Gov. Deval Patrick (D) said on Boston's WBUR this morning. And while "every hour, every day" brings investigators "a little closer" to finding out who was responsible, Patrick said everyone needs to "settle down and settle in for a long, painstaking investigation."
"This is the kind of investigation that requires picking up tiny pieces [of evidence] and scouring blocks ... a square inch at a time," the governor added.
Update at 8:05 a.m. ET. Pressure Cooker Lid Found?
CNN is reporting that the lid of a pressure cooker has been found on the roof of a building near the site of Monday's explosions.
Update at 8 a.m. ET: 100 Of The Injured Released, CNN Reports:
The latest estimate on how many people were injured, CNN says, is 183. And of those, about 100 are out of the hospital, the news network adds.
Note: As happens when stories such as this are developing, there will likely be reports that turn out to be mistaken. Monday, for example, authorities at one point said they thought there had also been an explosion at the JFK Library in Boston. But it turned out there had been a fire, not an explosion, and there's no known link at this time to the marathon attacks.
We will focus on news being reported by NPR, other news outlets with expertise and statements from authorities in position to know what's going on. And if some of that information turns out to be wrong, we'll update.