A New Hampshire lobster fisherman saved three people and two dogs from a burning yacht near New Castle on Saturday.
An investigation is currently underway into what caused the 70-foot yacht to burn and eventually sink, authorities said.
"We don't know what caused the fire and we probably never will because the boat burned down to the waterline and there is nothing left of the boat," Sgt. Steve O'Conner of the New Hampshire State Police Marine Patrol told WMUR-ABC.
Tom Hadley, from Hollis, New Hampshire, said he had noticed a bit of smoke coming from a yacht he had passed on his small fishing boat, and decided to turn around to offer his help.
The yacht, at the mouth of Little Harbor on the Piscataqua River, had burst into flames by the time Hadley came back to it. He told WMUR that he could see three people and two dogs standing on a platform in the stern of their boat.
Hadley said that they were holding pool noodles, so he yelled for them to jump into the water and then dumped his own lobster traps into the harbor to make room for the rescues.
"At first I hauled a lady on board and then we put the two dogs on board" Hadley told WMUR. "And then a younger man was half in, I hauled him over the side."
Hadley said he then saw a small fishing boat which he called over to help a third man who was clinging to the side as the heat coming from the boat increased.
"If there were an explosion the thought of being showered with burning fiberglass was not too appealing," Hadley said.
The three individuals were taken to the dock of the Wentworth Marina before being brought to Portsmouth Hospital, where they were treated, released and reunited with their dogs.
New Hampshire State Police reported that the two dogs were safe and unharmed.
A statement from the New Castle Fire Department only reported one minor injury among the three escaping the fire.
"If you ever think somebody is in distress out there, it doesn't hurt to cruise on over and check it out to make sure that they're OK," Hadley said.
The New Hampshire State Police received a 911 call about the boat fire just after 4 p.m., and was on site within minutes, according to a statement from the department.
According to police, the yacht, "Elusive", was headed toward the Wentworth Marina went one of the passengers noticed smoke below deck. The three passengers reported to police that the smoke had completely filled the boat within minutes.
Jarrod Tubbs, 33, of Jupiter, Florida, Kitt Watson, 67, and Diane Watson, 57, both of New Canaan, Connecticut -- a couple and their first mate -- lived on the yacht. As the boat has been completely lost, so have all of their belongings.
"This was just arms are open, come on board, get warm, we're going to take care of you and it really restored my faith in humanity," Kitt Watson told WMUR-ABC.
Marine Patrol, New Hampshire fire departments from Newington and Rye, the Kittery Harbormaster, and the Salisbury Fire Department from Massachusetts, assisted at the scene, state police said.
The tide pushed the burning yacht away from the coast, and after efforts by several agencies were unsuccessful, it sank in approximately 75-feet deep water, state police said. Within two hours of the initial 911 call, the boat had been submerged and will not be recovered.
The U.S. Coast Guard and the New Hampshire Department of Environmental Protection have been monitoring for any excess oil spillage from the sunken yacht.
A spokesperson for the New Hampsire Department of Environmental Protection told ABC News that a sheen of diesel fuel was seen as a result of the incident, but that crews are not aware of any shoreline impacts.