CONCORD — When the alarms sounded early Wednesday morning, the three firefighters on duty didn’t have far to go. Their own fire station was ablaze.
At first, the men did what anyone caught in a burning building would do — they escaped as quickly as they could, with only the clothes on their backs.
But as soon as they got outside safely, they immediately went to work, rushing to help their fellow firefighters extinguish a hot, smoky blaze that badly damaged a firetruck.
“It’s not that different from any other fires that we go to, except it’s our house,” Chief Mark R. Cotreau said after he surveyed the damage at Station 2.
The investigation into the fire was in its early stages, but officials believe it was probably started by an unknown problem with Engine 4 truck, which had been out Tuesday night.
Around noon Wednesday, the firetruck had been pulled from its blackened bay, where fragments of shattered safety glass lay around a pool of water and pieces of charred gear. The smell of the fire’s bitter residue still hung in the air.
Cotreau said the three men, Lieutenant Brad Ferrie, Firefighter Bill Haugh, and Firefighter Kevin Fagerquist, had returned with the truck from a minor call a few hours before the fire broke out around 12:45 a.m, triggering the station’s smoke alarms.
Without their gear, the three men did critical jobs at the perimeter as other firefighters arrived to fight the blaze, Cotreau said.
“Obviously it’s a traumatic experience, just like it would be for anybody else,” he said. “It’s their home away from home.”
The fire did not appear to cause any structural damage to the brick station, which dates to the early 20th century. Outside, a worker scrubbed the grime off an ambulance that was garaged there, and Cotreau said two other vehicles looked salvageable.
Officials said replacing the truck could cost about $600,000. Fires that damage firetrucks are not unheard of — in 2015, a firetruck in Acton was damaged by a blaze. Cotreau said he didn’t see any immediate connection between the two.
In the commercial district around the fire station, neighbors who are used to relying on the firefighters found themselves offering assistance.
Bob Carr, an owner of the West Concord Shopping Plaza, across Main Street from the station, said he has done business there since the 1960s. He recalled emergencies — at restaurants and a laundromat — when firefighters simply ran across the street to help.
As Cotreau stood on the sidewalk, Carr came out to ask if the station needed anything. The crew was welcome to park in the lot in front of the stores, he said. It was the least he could do.
“They’re just such good people,” he said. “They’ve been such great neighbors.”
Next door to the station at Colonial Motors, owner Richard Beers said he had walked over to a nearby coffee shop to start a tab for the station’s crew members, whom he has known for decades. Someone had already taken care of it, a manager told him.
The team at Station 2 has been playing an important role in the West Concord neighborhood, which has seen a number of new developments in recent years, said Town Manager Christopher Whelan.
“The firefighters are always there when people need them, and we are just glad none of them were hurt,” Whelan said.
Residents can be confident that the fire department remains ready for any emergencies, Cotreau said.
The town has a backup truck and will get help covering for the ambulance while it is out.
Crews will be able to mobilize from the Concord Municipal Light Plant when fires break out in West Concord, he said.
“We’re resilient,” Cotreau said.
John R. Ellement of the Globe staff contributed to this report. Andy Rosen can be reached at firstname.lastname@example.org.