A bombing near the finish line at the Boston Marathon Monday afternoon killed at least three people. For complete coverage, keep reading here. Visit this page for live updates.

One of the deceased was 8-year-old Martin Richard:

“He was so polite, composed, older than his years really,” Christina Keefe said of Martin on Tuesday morning. “I can see him now, holding his mom’s arm as she took them on their walks around the neighborhood.”. . .

Martin was often seen throwing a ball in his or his friends’ yards, or chasing his little sister. (Read the rest of the obituary here.)

Also present at the site of the bombing was Carlos Arredondo, a spectator who happened to be captured by a news photographer as he wheeled away a wounded man:

“Ambulance! Ambulance! Ambulance!” Arredondo yelled. A photo of him pushing this wheelchair while holding one leg of a pale, ash-covered victim would be on front pages around the country. As they went, one tourniquet slipped off. Blood flowed again. Arredondo grabbed the tourniquet and wrenched it tight. Finally, they found an ambulance. He lifted the man out of the chair.

Newspapers around the country reported on Arredondo once before several years ago, when he set himself on fire after learning that his son, a Marine, died in Iraq. Read The Post’s 2005 profile of Arredondo here.

Another man who appeared in many news photographs was Bill Iffrig, 78, who was steps from the finish line when the first bomb detonated. The shock knocked him to the pavement, but he continued running, Joel Achenbach writes:

Iffrig was on TV Monday night, describing what happened, his tone remarkably matter-of-fact:

“Everybody else is out there having fun and you got one or two people trying to destroy the whole thing, it’s hard to figure out. Terrorists, whatever they are…. I don’t have much use for it.”

This is why terrorists won’t win: Too many American like Bill Iffrig, who, when they get knocked down, get right back up again.

And yes, he finished the race. (Read the rest of Achenbach’s essay here.)

Mapping the hunt for Boston Marathon suspects

In the calmness with which Iffrig, Arredondo, and many others responded to the explosions, The Post’s editorial board saw a new recognition that we will not ever be completely safe from violence:

In the early moments after the blasts, there were indications of the nation’s maturity, for better and worse, in dealing with such shocks. Runners and onlookers seemed to respond, for the most part, without panic. Local police began cooperating seamlessly with state police and the FBI and other federal authorities. Emergency crews responded with professionalism.

Officials and reporters, meanwhile, were careful not to get ahead of the confirmed news. . .

Who was responsible? Again, there seemed to be a general understanding of the danger of jumping to conclusions. (Read the rest of the editorial here.)

At Wonkblog, Brad Plumer analyzes historical data on terrorist attacks, noting that it is probably premature to characterize the bombing as terrorism:

The FBI defines terrorism as “the unlawful use of force and violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives.” We still don’t even know if the Boston blasts qualify — or if they were the work of a crazy person with no goals at all.

As speculation about the identity of the perpetrator continued, Muslims around the world hoped that the attack had not been committed in the name of their faith. Max Fisher summarized the reaction of Muslims using social media:

Jenan Moussa, a journalist for Dubai-based Al-Aan TV, retweeted the message “Please don’t be a ‘Muslim’” and added that the plea was “The thought of every Muslim right now.” Moussa’s message was forwarded more than 200 times. . .

There will be displays of true sympathy from the Muslim world regardless of the religion of those responsible for the fatal blasts in Boston — as there were after both Sept. 11, 2001, and the deadly December school shooting in Newtown, Conn. Should the incident turn out to have even the slightest connection to a professed observer of Islam – a possibility that, according to Moussa and others, some Muslims are dreading – those gestures of support may look something like the handmade posters in Benghazi last September, a declaration of solidarity and a gentle reminder that Muslims despise terrorism just as much as anyone else. (Read the rest of the article here.)