In the middle of March, lifelong Chilmarker Mike Holtham was pulling out from his winter home on Quansoo when a group of fire trucks sped by, sirens blaring. Curious, he made a split-second decision to follow the trucks, which were headed to a fire on a road nearby.

“I know every person that lives on that street right now,” he remembered thinking as he approached the scene. “Now there’s no excuse,” he thought.

The next day, Mr. Holtham walked into the Chilmark fire station and signed up to be a volunteer firefighter.

“Growing up in Chilmark and Menemsha, I knew that it was something I was going to do at some point,” said Mr. Holtham Wednesday afternoon, taking a break from grill duties at the town firemen association’s annual Backyard Bash fundraiser.

But in a department where car accidents and small structure fires make up a good chunk of the calls, Mr. Holtham certainly never expected to battle a blazing inferno like the one he was called to a few months after joining the squad.

He was enjoying a quiet afternoon off from his six-day-a-week restaurant job when he was first called to the scene of the fire in Menemsha. At first, he predicted a small fire in one of the village shops. But as he drove to the fire station, calls poured in asking for responders from all six Island towns. “I got to [the] fire station here and could see the cloud of smoke from halfway across the Island. So it definitely got the blood pumping,” Mr. Holtham said.

Apart from a chimney fire and some car accidents, the blaze that destroyed the U.S. Coast Guard boathouse and surrounding town pier in Menemsha was the first big structure fire Mr. Holtham had ever fought. “It was really intense. I was one of the first guys there, so we ran the first attack line. To be right up next to the inferno was an eye-opening experience,” he said. “Hot. Hot is one adjective. But the adrenaline running through you is like no other.”

It was hard to imagine that blinding heat on Wednesday as the boys in their navy blue Chilmark Fire Department T-shirts buzzed around getting ready for the backyard bash. Tougher still was the thought that these smiling firefighters just a few weeks ago were battling intense dehydration and fatigue as they conquered a blaze that might otherwise have reduced the historic fishing village to a pile of cinders. Chaos is a word that comes to mind.

Or perhaps not. “A lot of people call it chaos but it is what we train for,” said Ian Yaffe, a 10-year veteran of the Chilmark volunteer firefighters who recently relocated to Maine. He wasn’t present the day of the Menemsha fire, but stayed in contact with his friends in the department throughout the ordeal. “From all accounts that I heard it was really a measured response,” he said.

Mr. Yaffe has worn many hats around town, and also acted as deputy harbor master in Menemsha before he moved away. But he’s been a firefighter since he was 18, and it’s stayed with him, thanks to the tiny but committed department in which he trained. Now, he’s in a paid fireman position part-time.

“The firemen, they’re dedicated. They’re community-minded people,” said Chilmark firemen’s association president and longtime volunteer firefighter Donald Poole. “They realize that there’s nobody here that’s going to do this kind of stuff unless we step up to the plate. So it becomes like a club of guys who care, and not just about the fire department. Whatever happens in town, we’re the kind of guys that would help you. If your car gets stuck or your battery dies or you lose your dog or something — these are the kind of guys that just come out and help people.”

And just like Mr. Holtham and Mr. Yaffe, who spent summers on the Island when they were growing up, many of the young men raised in the community are eventually inspired to join the force. “It’s just one of the things that we do. So pretty much most of the guys who grew up around here do it,” Mr. Poole said.

Which doesn’t make it any less of a commitment to those who sign up. “All these guys are taking time out of their busy day, their busy schedule. And it’s summer, it’s our time to make money on the Vineyard,” said Mr. Holtham of the sacrifices made by the volunteers.

The firefighters were scheduled for a fire drill on the day the fire broke out. Instead, they got the real thing, and had to fight a fire far bigger than most will see again in their lifetimes. In the weeks since, the changes have been subtle, but present.

“I like to have a good time and laugh it up and ham it up quite a bit, but the next few weeks were still just kind of pondering what I’d seen and witnessed. So it was a very humbling experience, for sure,” said Mr. Holtham.

The town has been gracious in the aftermath, according to Chilmark fire chief David Norton. “They’re all being praised,” he said of his volunteers. “They’re all being patted on the back. ‘Good job, well done.’” But they’re not taking all the credit.

Mr. Holtham said he was blown away by the cooperation among all the Island’s emergency response teams. “To see the way that the individuals came together as one core group, all six towns, to coordinate so well and to really avoid what could have been a complete tragedy,” he said.

His shell-shocked, post-fire mood appears to have lifted, but the experience clearly had a lasting effect. And he’s grateful for the bonds that the fire ended up forging within his own force and among others on the Island.

“The best part of it is it really brings everyone together. Jeremy [Bradshaw, fellow Chilmark fireman] and I, we fought the fire together. For the most part he and I were backing each other up. I met the guy one other time before that and I feel like I’ve got a new best friend. That’s like the real brotherhood that comes together with this whole thing,” said Mr. Holtham.