Michael Young said a colleague's death has left a somber mood at Denver fire stations.
Lt. Rich Montoya of the Denver Fire Department died Sunday in the line of duty.
Young said the tragedy may make his wife, Leigh, worry more than she already does.
Her husband is a technician on the fire department and their son, Travis, is a Craig Police officer. Their youngest son, Seth, is a teacher at Craig Intermediate School.
Leigh may fret about having both sons far from home and her family at risk every day, Michael said. But he understands the dangers of his job and is ready to accept whatever happens.
"When it's my time, it's my time," he said. "There's nothing I can do about it. I just have to do the best I can and hope my experience will get me through."
Michael said he sees death every day.
"You kind of keep it at arm's distance so you don't feel the direct impact," he said.
But when it's a fellow firefighter, it's not always easy to move past the loss.
Michael and Montoya were in the same probationary class in 1976. Montoya was No. 1 in the academy class; Michael was No. 3.
During their tenure with the department, the two worked at different stations but knew each other and trained together.
"The day that he (had a heart attack) at that fire, we were training together," Michael said.
Crews trained for two hours on the morning of May 14 doing a large area search. Later, both went to a hazardous materials call where they evacuated a high-rise apartment building.
The HazMat situation wrapped up at 8 p.m. A house fire call came in at 4 a.m.
Fire officials said Montoya had a heart attack and was found under a mattress in the second floor of the house.
Michael said firefighters, who are all required to be emergency medical technicians, began CPR on Montoya immediately after Montoya was rescued from the building.
After a week in a drug-induced coma, Montoya's family removed him from life support Sunday.
Michael said he was unsure exactly what happened or how the mattress fell on Montoya.
"No one knows, and nobody ever will," Michael said.
Firefighter Byron Willems, the crewmember with the longest career at Craig Fire/Rescue, said the incident hit home for him, especially because Montoya was just 15 shifts away from retirement.
"You never know -- your last one could be your last one," Willems said.
Craig Fire Chief Chris Nichols said situations such as these call for introspection.
"Anytime there's a death of a fellow firefighter, we all take a moment to pray for them No. 1, and No. 2, to reflect on our careers as firefighters and the sacrifices we make," Nichols said.
Montoya's heart attack happened during a structure fire, similar to those Craig Fire/Rescue responds to regularly, he said.
"It can happen at any time on any call," Nichols said. "We respond to the exact same type of call. But we respond with less manpower."
No one has been killed in the line of duty in Craig, Willems said. But can understand how a heart attack could take the life of a firefighter. He's 47 and nearly ready to call it quits. Montoya was 61.
"The No. 1 killer of firemen is heart attacks," Willems said. "The physical load of doing what we do is unbelievable."
Michael said Montoya accepted that load willingly and proudly.
"He took his job very seriously," Michael said. "He was a dedicated guy. He was a good officer."
Nichols said the hearts of Craig firefighters extend to Montoya's friends and family. He regrets their loss and is thankful no one from Craig has perished in the line of duty.
Still, the thought lingers with firefighters.
"What we do is an inherently dangerous job," Nichols said. "We take calculated risks anytime we respond to an emergency.
"The unthinkable is always in the back our minds."
The Associated Press contributed to this story.