A commercial building on Edgartown-Vineyard Road in Oak Bluffs was significantly damaged Wednesday when a fire started in a nearby van.

A witness saw smoke coming from a work van parked at 79 Edgartown-Vineyard Haven Road around 9:15 p.m. The flames then spread to a second van and then to the building, which is home to several construction businesses, said Oak Bluffs fire chief Nelson Wirtz. 

The fire traveled up the wall of the building and inside, torching stored trim boards, cedar shake shingles and other materials that were stored inside.

“There was a lot of fuel,” Mr. Wirtz said. “There’s a few different businesses whose equipment was significantly damaged.” 

The fire, which reached a second alarm, brought firefighters from Tisbury, West Tisbury and Edgartown to aid Oak Bluffs crews. They were eventually able to put the fire out. Four people who were inside the building were uninjured. 

Two firefighters were injured while fighting the fire, and were later treated and released from Martha’s Vineyard Hospital, Mr. Wirtz said. 

The building was not habitable Thursday morning, as firefighters, Eversource and the town’s building and electrical inspector checked out the building. 

The cause of the fire is under investigation. 

The building belongs to MV Green Villa LLC and is valued at $656,200, according to town records.