Police have identified the two people who were found dead on a boat that was docked on Fire Island over the weekend.

Peter D'Ancona, 54, and his girlfriend Tina Sgambati, 51, both of Moriches, were found dead in a boat Sunday afternoon in Cherry Grove, police say.

The 35-foot Mainship boat was docked behind Cherry's on the Bay Restaurant and Bar.

Police say the deaths appear to have been caused by carbon monoxide poisoning. It is not known if there was a carbon monoxide detector on board.

The couple had left their condo complex in Moriches Saturday afternoon and were due to return on Sunday.

D’Ancona was a former U.S. Marine and a retired FDNY firefighter who spent countless hours at Ground Zero after Sept. 11. He owned a roll-off dumpster contracting company based in Medford.

Family and friends say they are heartbroken.

"He's the most hardworking man ever. I've never met somebody that worked harder than him," says Peter D'Ancona's son, Pete D'Ancona. "He was working up to an hour before he got on the boat on Saturday. And it was the first time this season he put the boat in the water, and this happened."

Cherry Grove is one of the family's favorite getaway spots. The younger D'Ancona says he had messaged back and forth with Sgambati as the couple was having fun on Fire Island, but then he couldn't get in touch with them after Sunday morning. He says the last message he received from Sgambati said, "Wish you were here babe."

Pete D'Ancona says his father will be remembered as being generous to everyone he met.

"He always gave me and my sister anything we wanted. Nobody will forget him," he says.

The source of the suspected carbon monoxide is unclear. Anyone with information on the case is asked to contact authorities at 1-800-220-TIPS.

Autopsies will be performed to determine the exact cause of death.