It was a day that was supposed to demonstrate the best of the human spirit—but was instead marred by the worst.
Shell-shocked athletes are still grappling with the horrifying scene that played out after two bombs exploded around the four-hour mark of the Boston Marathon, shattering nearby glass windows and knocking runners off their feet as they approached the finish line.
Spectators were jam-packed around the finish line when the twin blasts went off almost simultaneously, putting hundreds within what authorities called “life-threatening and limb-threatening” distance from the source of the explosions. One witness reported seeing blood “everywhere instantly,” while medical personnel described the scene as having an astonishing amount of carnage among the civilian population.
“This is what we expect from war,” Alasdair Conn, chief of emergency services at Massachusetts General Hospital, told CBS News.
More than 176 people were injured Monday. Tents meant for recovering runners were turned into makeshift medical facilities, with dozens of victims being brought in without limbs.
"Some guy told us it was really bad, that several people lost their legs, there were amputations and not to go through to finish line area," James Minicucci told CBS News. Minicucci was on his way to the finish line when he heard the explosions.
Dr. Peter Fagenholz with Massachusetts General told CBS Boston that his hospital performed several amputations.
The quick response by medical personnel has been credited with keeping the number of casualties low, with just three reported dead. Due to the proximity of so many people to the explosions, that number could have been much higher.
One child has been reported among the dead. The 8-year-old boy was reportedly waiting for his father to finish the race when the bombs went off. CBS Boston says his mother and sister were injured.
A second victim, 29-year-old Krystle Campbell, was identified Tuesday afternoon.
Thirty-nine runners from Colorado Springs participated in the race, according to the Boston Marathon website. All have been accounted for and are unharmed.
As of Tuesday morning, no motive for the attack has emerged, and no one has stepped forward to claim responsibility. President Obama carefully avoided using the terms “terror” or “terrorism” in his address to the nation. There was no intelligence in the days leading up to the race indicating the possibility of any kind of terrorist attack. The Pakistani Taliban has reportedly denied any involvement.
Nevertheless, a White House official later said that the explosions at one of the world's oldest and most prestigious races was being treated as terrorism.
U.S. Rep William Keating with the Homeland Security Committee said the nature of the attack has all the hallmarks of a domestic or international terrorist incident. He told the Associated Press that the international nature of the race, which attracts elite runners from around the world, as well as the fact that it fell on Tax Day, provide both foreign and domestic terrorists motivation.
Keating has not been formally briefed on the investigation.
Obama received updates overnight from his Assistant for Homeland Security and Counter-terrorism, Lisa Monaco, and was to get further briefings from senior administration officials later Tuesday morning.
"We still do not know who did this or why, and people shouldn't jump to conclusions before we have all the facts," the president said in brief remarks Monday evening. "But make no mistake: we will get to the bottom of this. And we will find out who did this. We will find out why they did this. Any responsible individuals, any responsible groups, will feel the full weight of justice."
Investigators obtained a search warrant Monday night for an apartment in Revere, Mass., a Boston suburb. CBS reports that the search was related to a Saudi national under guard at Brigham and Women’s Hospital. That man was seen running from the explosion, and was then chased down and tackled by a witness. He was turned over to Boston police, then the FBI, and has reportedly been cooperating with the investigation. He’s denied any involvement, and has not been named a suspect.
The Revere Fire Department wrote on its Facebook page that the apartment search pertained to “a person of interest.”
CBS Boston reports that several bags were removed from the scene around 2 a.m. EST Tuesday.
A source told CBS Tuesday afternoon that the Saudi national is no longer considered a person of interest, and is now considered a witness.
In a news conference Tuesday, authorities said that the investigation is expected to take a lot of time, with the site of the bombings likely to be a crime scene for several days. Boston Police commissioner Ed Davis called it the most complex crime scene in the history of the department.
The biggest revelation from Tuesday's news conference was that the two explosives that went off were the only two explosives found. There were rumors swirling Monday that at least two undetonated devices were also found.
The Boston Police Department says two bomb sweeps were made prior to the marathon, uncovering nothing.
More details about the explosives also emerged Tuesday. They have been described as "low explosive with anti-personnel" packing. Law enforcement told CBS News that they were made to look like discarded property. They were reportedly made from pressure cookers with metal and ball bearings.
The source told CBS News that one of the devices, found near the Starbucks on Boylston Street, appears to have been placed in a metal pressure cooker, which is a kitchen pot with a locked down top. That device had been placed in a nylon bag or backpack, the source said.
11 News continues to follow all updates out of Boston. Keep checking here and on kktv.com for all the latest information.