Investigators continued working at the Rhode Island Yacht Club on Monday to determine the cause of a blaze that burned six boats – including several that sank – and damaged a portion of the dock,

“I think it’s a significant loss,” said Cranston Deputy Fire Chief Stephen MacIntosh.

The blaze was first reported at approximately 11:30 p.m. Saturday, said MacIntosh, and at one point roughly 40 personnel were at the scene. It took hours to fully extinguish the blaze, he said, given the challenges in terms of the materials that were burning, such as fuel and fiberglass, as well as difficulties in accessing some areas of the boats and grappling with the heavy smoke condition.

“We had blackout conditions just from smoke issues,” said MacIntosh. “[Firefighters] were in the smoke, working within the smoke” and using air packs for the entire time.

Six boats were “completely demolished” by the flames, said the deputy chief, and a handful of others sustained residual damage. Three of the boats – including the one witnesses identified as the starting point of the blaze – completely sunk, while a fourth was partially submerged.

Initial responders found several people trapped on the dock by flames, MacIntosh said, and a fireboat safely rescued them. Two people were hospitalized as a result of the blaze – a firefighter with a minor injury and a civilian experiencing a medical emergency – although both were treated and released. No other injuries were reported, he said.

MacIntosh said weather conditions provided a break to responders, with the wind blowing out onto Narragansett Bay and carrying some of the smoke away. The use of fire-suppressing foam was needed in fighting the blaze, he said.

“Once we arrived on scene, no additional boats became involved,” he said.

Some people were sleeping on their boats at the time, and the deputy chief spoke highly of the efforts many made to alert others of the situation.

“The folks that were on the dock…they did attempt to notify some of the neighboring boats,” he said. “Thank you to the neighbors who were looking out for their neighbors…They enjoy their boats, and some of them live on their boats. It’s a whole community down there.”

MacIntosh said the investigation will center on examining the sunken vessels, and given the “monumental efforts” required to raise and dry out the boats the insurance industry is currently taking the lead. He expects fire personnel will remain appraised of the investigation, although he cautioned conclusive evidence may not be found given the extreme nature of the fire.

“Sometimes your evidence is destroyed. We won’t know until we get inside,” he said.

Various support personnel, including Department of Environmental Protection officials and the state fire marshal’s office, also responded to the scene. MacIntosh said DEM began efforts to contain and clean the fuel and oil that spilled into the water, with Clean Harbors expanding that part of the response.

Fire personnel from neighboring communities provided coverage at Cranston stations in the early hours of Sunday morning.

“The rest of the city was protected,” said the deputy chief.

On its website, www.riyachtclub.org, the club reached out to the community and its members.

“A sad day for the Rhode Island Yacht Club, as fire broke out at the marina, Saturday night May 10,” reads the posting. “We extend condolences to all the members who were affected by this tragic accident. More information will follow.”

Michelyn Saccoccio, the club’s social chair, said the board was scheduled to meet Monday night to discuss the situation further.

“We’re still trying to figure out exactly what happened,” she said.

The nearly 140-year-old club in December celebrated a major three-year restoration project, which included the reconstruction of the foyer, the addition of an elevator, other accessibility improvements, the creation of a new third floor that serves as office space, new walls and the replacement of leaky windows.

The weekend’s scene brought back memories of the fire that destroyed the Edgewood Yacht Club in January 2011.

Wayne Kezirian, the Edgewood club’s commodore, recently appeared before the City Council to share the status of rebuilding plans. He said the current schedule calls for driving piles in August, with an opening date in time for next year’s boating season.