Suzanne Rozdeba Firefighters at Engine 28 and Ladder 11 mourn Roy Chelsen, who died Sunday of bone-marrow cancer and was credited with saving the lives of 11 of his colleagues on Sept. 11.

Courtesy of FDNY

Already, the south tower of the World Trade Center had collapsed. But as Kevin Murray and Roy Chelsen huddled with their fellow firefighters for safety in the lobby of the north tower on Sept. 11 – debris and bodies falling all around them outside – no one knew what had happened.

“Roy ran out to leave, and realized the whole other building wasn’t there,” Mr. Murray recalled in an interview earlier today, describing how Mr. Chelsen, who died Sunday, saved the lives of 11 of his fellow firefighters. “He turned around, and ran all the way back to get us. He ran through it three times to get us out. He convinced everybody that we had to go because it looked like the north tower was coming down.”

In all, Mr. Murray and Mr. Chelsen worked side-by-side for eight years as firefighters in the East Village. And they were side-by-side again Sunday just hours before Mr. Chelsen died after a long battle with bone-marrow cancer at age 51.

At Engine 28 and Ladder 11 firehouses in the East Village, the mood was somber today after firefighters learned of the death of Mr. Chelsen, whose cancer had been linked to his work digging through the rubble at Ground Zero in the days and weeks after the attacks.

But Mr. Murray, who still works with Ladder 11 on East Second Street, said that the sadness at the firehouse was tinged with something else.

“Of course everybody’s upset,” said Mr. Murray, who’s 36. “But nobody wanted to see him suffer anymore.”

A day after Mr. Chelsen’s death, a Facebook page maintained by Mr. Murray was flooded with messages for Mr. Chelsen and his family; many of the notes alluded to Mr. Chelsen’s heroism, an oft-recounted story of 9/11.

Mr. Murray remembered how he and Mr. Chelsen found themselves in the north tower on Sept. 11. “I got sent to Ladder 18, another company, on 9/11. Everybody from Ladder 11 was killed; I was the only one that survived,” Mr. Murray said. “When we came down to the lobby, the south tower had collapsed, but we didn’t know that. It seemed a lot of companies wanted to stay in the lobby because it was safer because of the jumpers and the debris.”

It wasn’t until Mr. Chelsen saw that the south tower had fallen that the other firefighters realized that it was safest for them to leave.

But Mr. Murray said that his friendship with Mr. Chelsen transcended that awful day.

They worked together until Mr. Chelsen retired in 2006, spending time between fighting fires by taking in all that the East Village had to offer. “We would go down to Il Bagatto, an Italian restaurant on Second Street,” Mr. Murray said. “He’d park his motorcycle there. He had a 343 painting on it, and everybody was asking him questions about it.”

The 343, Mr. Chelsen would explain, represented the number of firefighters who died at the World Trade Center.

On Sunday, Mr. Murray was at his friend’s bedside in Warwick, N.Y., before he died. “I was with him yesterday, right before he passed. He wasn’t responsive yesterday. It was more about being there for the family.” Mr. Murray was joined by some of Mr. Chelsen’s closest friends, including several firefighters. “They say that hearing is the last thing to go, so we were cracking jokes, and hopefully he heard us,” he said.

Courtesy of Kevin Murray Roy Chelsen, third from left, with other survivors of the north tower at the World Trade Center (from left): Jim Ippolito, Brian Becker, Bob Salvador and Kevin Murray.

Terrence Mulholland, 44, a firefighter with Engine 28 and close friend of Mr. Chelsen, told The Local, “I was devastated. It all took us by surprise that it happened so fast. I love the guy. I missed him when he retired, and now I miss him even more.”

Mr. Mulholland and Mr. Chelsen had worked together at the firehouse for 10 years. “He was a fixture down here for a long time,” said Mr. Mulholland. “People in the streets that need you get to know you, and people knew who he was.”

Just last month, Mr. Chelsen finally got a much-needed stem-cell transplant after a long search for a donor. “Things were looking good,” said Mr. Mulholland.

Mr. Mulholland last spoke to his friend on the phone last week. “It’s like losing a family member, when you live with somebody 24 hours a day,” he said.

Firefighters consider themselves a brotherhood, and Mr. Chelsen was a huge part of that circle with members of both firehouses. “He was a big-hearted guy who loved his family. He was a dedicated fireman, and all-around great guy,” said Mr. Mulholland.

Plans for the wake and funeral are still under way. Mr. Chelsen is survived by his wife, Patricia, and son Christopher, 24.

Peter Gleason, a former firefighter who also worked alongside Mr. Chelsen at Engine 28, told The Local that one of his favorite memories of working with Mr. Chelsen in the East Village was getting a lift from him on his Harley. “I remember he would occasionally, even in the coldest part of winter, come to work in the East Village on his Harley Davidson,” Mr. Gleason recalled. “I’d have to walk over to the firehouse from the Astor Place subway stop. He’d pick me up and give me a ride over there.”

He added that one of Mr. Chelsen’s greatest contributions has been the attention he brought to the New York Blood Center. “When Roy got sick, he utilized that to help the blood bank increase their bone marrow registry,” Mr. Gleason said. “That’s the legacy Roy is leaving behind.”

Mr. Murray said that Mr. Chelsen also left another legacy.

“Not only did he save me that day, but he inspired me to be like that, and not just me, but a lot of people, just by the way he was,” he said. “He was considered the toughest guy in the firehouse, and he was until the day he died.”