Around one-third of Constitution Marina in Charlestown, Massachusetts, was destroyed in the blaze

An overnight fire Tuesday that sank two houseboats and destroyed a third at Constitution Marina in Charlestown, Massachusetts, reignited Wednesday afternoon, forcing firefighters to return to the scene and sparking concerns about fuel leaking into the harbour.

Oil containment booms are in place at the marina, with boat owners who live there year-round not sure when they would be able to return to their homes.

As many as 50 firefighters battled the Tuesday night blaze, attacking the fire from the marina, a nearby bridge and using fireboats.

Boston Deputy Fire Chief Robert Calobrisi told WHDH-T that on-board fuel from the boats kept feeding the fire.

“I got to believe there was some diesel fuel onboard one of the larger boats that kept stoking the fire and as soon as you hit it and darkened it down, it would reignite again,” he said.

Walter Hope, who lived on one of the boats for 15 years, said he scrambled to extinguish the fire but it became too overwhelming.

“These are people’s homes. They’re not luxuries,” he said. “We tried to put the fire out. We used six different fire extinguishers but it just kept coming back.”

The Coast Guard says it’s not clear how much fuel spilled into the harbour, but the fear is that more will spill when salvage crews attempt to raise the sunken boats.

About 200 people live in the marina year-round, and a nearby hotel offered rooms at a discounted rate to the residents who couldn’t stay on their boats due to the fire.

The cause of the flames is still under investigation.