MATTAPOISETT, Mass. (WPRI) — Investigators believe a massive fire that destroyed boats, vehicles and buildings at Mattapoisett Boatyard last week was accidental in nature.

State Fire Marshal Peter Ostroskey and Mattapoisett Fire Chief Andrew Murray released a joint update Monday saying they believe the fire started when a spark ignited gasoline vapors while a worker was replacing a boat’s gas tank inside one of the buildings.

The resulting explosion sent the worker to Rhode Island Hospital with significant injuries.

The owners of the boatyard identified the worker Monday as Phil Macomber. They said he remains at the hospital with major burns and a shattered femur. While he’s expected to survive, he has a long road to recovery ahead.

A GoFundMe page was set up to collect money for Macomber’s medical expenses. As of 9:30 p.m. Monday, it had already raised almost $134,000.

More than 100 firefighters responded to the six-alarm fire on Friday. After the initial explosion, officials said strong winds coming off the water fueled the flames and caused them to spread to six buildings, as well as many of the vehicles and boats nearby.

Nearly four dozen vehicles were damaged, according to fire officials, while the boatyard’s owners said 20 boats were lost.

Three firefighters were taken to the hospital for heat exhaustion and smoke inhalation. All three have since been released, according to fire officials.

The fire was out by about 6 p.m., but crews remained on scene throughout the night to dig through the rubble and make sure it didn’t flare back up.

Mattapoisett Boatyard has been in business for more than 60 years. Owner David Kaiser released a statement Monday saying they’re essentially starting over from the ground up, having lost all of their tools, equipment, inventory and paperwork, but he assured this isn’t the end.

“To be sure there is no misunderstanding, we plan to come back from this better and stronger!” Kaiser wrote. “I heard myself saying that day, “It’s not a question of if we will rebuild, it’s a question of how tall and how wide!” The Boatyard will be here for you!”

Kaiser said the business will be setting up temporary shop at its Route 6 location. The waterfront, docks and launches off Ned’s Point Road weren’t affected by the fire, he noted, and the hope is to have the yard cleaned up for parking by this coming weekend.

The business will, however, have to restore its schedules and records that were “always handled the old-fashioned way” on paper.

“To reconstruct these records will not be easy,” Kaiser said. “We would ask any of you who have not received a launching bill, mooring or other service invoice to let us know. Something of the Honor System. Your help in this will be very much appreciated!”

Kaiser thanked first responders for their efforts during Friday’s fire and their customers, friends and community for the “overwhelming” amount of outreach and support since.

“As much as we would never wish this tragedy on anyone, the way that so many have rallied around us has been incredible,” he wrote. “We have always loved our town and our wonderful community. We never realized the profound effect this horrible event would have on so many others. It’s impossible not be feel emotional and deeply moved by other’s efforts to help out.”