WATERFORD – A 65-year-old Massachusetts man died Sunday afternoon while swimming at Keoka Lake.

Oxford County Deputy Tom Harriman said the incident began around 3:30 p.m. when the man had “some sort of medical emergency while swimming.”

Harriman said the man’s family was in a sailboat next to him and they pulled him out of the water as soon as they noticed him having trouble.

“The family got him up on the dock and performed CPR on the man until medical help arrived,” said Harriman. “He was taken to Bridgton Hospital, where he was pronounced dead.”

Stoneham Rescue and United Ambulance responded to the scene.

The Oxford County Sheriff’s Office declined to release the identity of the Attelboro, Mass., man, because not all family members had been notified as of Sunday evening, an officer said.

The dead man owned a summer cottage off Howard Trail, and according to Harriman, swam the same route on the lake every day.

“He was swimming from the dock at the shore to an anchored dock about 30 to 40 feet into the lake,” Harriman said. “He began having trouble when he reached the anchored dock.”

As of Sunday night the Oxford County Sherrif’s Department had yet to determine a cause of death.

“We’re not sure what kind of medical emergency caused him to struggle out there,” Harriman said. “But it was not a drowning.”