There were hundreds of heroes in the aftermath of Monday's tragic bombing attacks in Boston. Doctors, police officers and even former NFL players responded with tremendous courage and saved lives. Carlos Arredondo — easily recognizable in photos and videos because of his cowboy hat — was one of those heroes and is prominently featured in two of the more memorable and traumatic images from Monday's attack.

In the above photo, Arredondo can be seen apparently holding together the femoral artery or tourniquet of a victim who had lost both his legs in the attack. "I kept talking to him. I kept saying, 'Stay with me, stay with me,' " Arredondo told the Press Herald.

And at the 1:45 mark of the video below, you can see Arredondo rushing to help victims just seconds after the first explosion.

But who is Arredondo? As several tipsters and and publications have noted, the 52-year-old has quite the past.

Arredondo was watching the race to support a runner who was running the marathon in honor of Arredondo's son, Lance Cpl. Alexander S. Arredondo, who was killed in Iraq in 2004. When Arredondo was told (on his 44th birthday, no less) about his son's death by a group of Marines, he didn't believe them. From a 2007 New York Times article:

"I just screamed," he said. "I said ‘No, no! It can't be my son.' "

Mr. Arredondo said he "lost it." He ran to his garage and grabbed a gallon of gasoline and a propane torch.

He took a sledgehammer and smashed the government van's windshield and hopped inside. As the officers tried to calm him, Mr. Arredondo doused himself and the van with gasoline and lit the torch.

There was an explosion, and the officers dragged Mr. Arredondo to safety. He suffered second- and third-degree burns over 20 percent of his body.

"I went to my son's funeral on a stretcher," he said.

The incident – and the 10 months he spent in the hospital recovering – spurred Arredondo to a life of activism protesting the war in Iraq. He drove around the country in his son's truck, which was carrying a coffin and was decorated with pictures of his dead son at his funeral. "As long as there are marines fighting and dying in Iraq, I'm going to share my mourning with the American people...Every day we have G.I.'s being killed, and people don't really care enough or do enough to protest about how the war is going," he told the Times. "Some people say I'm dishonoring my son by doing this, but this is my pain, my loss."

That loss grew exponentially four years later, when Arredondo's surviving son killed himself at age 24, partly out of grief from losing his older brother. Now, Arredondo has again found himself in the midst of tragedy and again responded with resiliency and courage. Below is an interview with Arredondo taken after the bombings.

[Image via AP]