Ed Kelly is the head of the state firefighters association, but he’s no desk jockey. He’s a working firefighter, and on Tuesday night, 27 hours after Boston changed forever, I followed him up the stairs at the District 4 station on Columbus Avenue that houses Ladder 17 and Engine 7 in the South End.

“Here’s the deal,” Kelly said, stopping me before we went in the room. “They don’t want their names in the paper. They don’t want to be singled out. They did what every firefighter in the city did. What every cop, every EMS worker, did. They don’t think they’re special.”

What they did was nothing short of heroic. They ran toward the bombs. They saved lives.

One of the firefighters from Engine 7 is a Marine who did three combat tours in Iraq and Afghanistan. He saw bad things overseas. He didn’t expect to see them in the Back Bay on Patriots Day.

“We were on a call, Comm. Ave and Exeter,” he said. “There was a barbecue on the porch. College kids.”

Their gruff lecture on fire safety and common sense was cut short when the first bomb exploded around the corner.

“I know what a bomb sounds like,” he said. “We tore around the corner thinking we were going to find a fire. But there was no fire.”

Instead there were dozens of people spilled on the sidewalk. The firefighters worried about secondary bombs and biological weapons. But they dove into their work.

“The first person I encountered was a woman. The bone was sticking out of her leg. Four inches in width, 10 inches in length. The femoral blood was a dark, dark red.”

A 12-year department veteran from Dorchester was right next to him, working through the victims in front of Marathon Sports. He saw a guy he knew from the neighborhood, Bill Richard.

“I can’t find Denise,” Richard cried, referring to his wife.

The Richard family had been caught in the blast as they watched runners pass the finish line. Bill Richard and his son Henry avoided serious injury. But Denise Richard was hit in the head with shrapnel, and her 6-year-old daughter Janey lost part of her leg. Eight-year-old Martin Richard caught the full force of the explosion, and when the firefighter looked down at him, “I knew Marty was gone.”

Marty Richard was a third-grade classmate of the firefighter’s daughter. In fact, almost everyone on Engine 7 knew the Richards; the lieutenant’s kid was a classmate of one of the Richard kids.

“My daughter goes to the same Irish step dance school as Janey Richard,” Ed Kelly said. “This is the thing. All these guys, they’re neighborhood guys. When they were working on these people on Boylston Street, in some cases they were working on friends and neighbors, and they were working on strangers just as hard. They saved many lives.”

One of those strangers was a homeless man, whose foot hung by a thin shred of flesh.

“I looked him in the eye and asked him if he was OK,” the former Marine said, “but he was in shock. He couldn’t talk.”

The Marine was treated for post-traumatic stress disorder after his last combat tour. I asked him if he needed more treatment after what he went through on Monday.

He didn’t answer for a while, then nodded slowly and said, “Probably.”

Another former Marine was on Ladder 17, and when he jumped down from the truck and waded onto the bloodied sidewalk he had to make a choice: which child to grab first.

“There were two kids missing legs,” he said. “I grabbed one of them and another guy grabbed the other kid.”

He and an EMT tried to put a tourniquet on the boy’s leg, but the blood made the tubing slippery.

“It’s OK, buddy,” the firefighter told the screaming boy. “It’s OK, pal.”

Ed Kelly had brought his kids to watch his wife run the Marathon. She had just crossed the finish line and had walked down Boylston toward Berkeley when the first bomb went off. Kelly ran down Berkeley Street, burst into the station house, and grabbed his gear from his Ladder 17 locker and ran back to the bomb site.

“A lot of off-duty guys did the same. Not just firefighters. Cops, EMS,” Kelly said. “It says something about this city.”

I asked one of the firefighters, the former Marine with eight years on the job, why he and his brother firefighters did what they did, without any concern for their own safety. Why they ran toward the bombs. Why they were prepared to die if need be.

“That’s our job,” he said, shrugging.