UPDATE: Three Dead, 100+ Injured in Boston Marathon Bombing


Updated at 10:44 a.m. on Tuesday: Three are dead, including an eight-year-old boy, and at least 140 are injured after two bombs exploded near the finish line of the Boston Marathon, CNN.com reported Monday evening. The explosions shook Copley Square around 2:45 p.m., more than two hours after the first finishers.
Officials are working on “several active leads.”
According to nearby hospitals, eight children were among the injured. Doctors have reported many of those harmed in the incident sustained shrapnel injuries.
Nearly 27,000 people were competing in the race, which was called off after the explosions.
President Obama addressed the nation around 6:15 p.m., saying, “We still do not know who did this or why … but make no mistake: We will get to the bottom of (this). We will find out who did this. We will find out why they did this. … Any responsible groups will feel the full weight of justice.”
Two other devices were found and dismantled, according to U.S. Rep. Bill Keating, D-Massachusetts. One was found at a Boylston Street hotel. The location of the other bomb was undisclosed, reports said.
Keating called the events a “sophisticated, coordinated, planned attack.”
According to a report from NBC Latino,  Carlos Arredondo, of Portland, Maine, was one of the many heroes to respond immediately after the explosions. 
Arredondo is the man seen in photos wearing a cowboy hat and appears to be pinching shut a protruding artery from a victim’s thigh. 
Gawker identified Arredondo as a peace activist. Arredondo’s son, Lance Cpl. Alexander S. Arredondo, was reportedly killed in Iraq in 2004, and he was there to support another man running in his memory. 
Both Red Cross and Google have created websites for friends and family to find loved ones who were competing or in the Boston area at the time of the incident.
(Photo by CNN.com)