A 17-year-old who disappeared while swimming with friends in Connecticut on Memorial Day is presumed dead, officials said Tuesday.

The search for the unidentified teen is now a recovery mission after he disappeared in Candlewood Lake in New Milford, setting off a frantic response by witnesses, boaters and, later, emergency crews in the waters between Dike Point Park and Rock Island, WVIT reported.

New Milford Mayor Pete Bass told the Danbury News Times that divers would resume their search for the teen early Tuesday at Dike Point Park, where he celebrated a day earlier with friends.

Police Sgt. Jim Dzamko told the newspaper that divers were hampered by murky waters and stopped searching for the boy after sundown on Memorial Day.

“This is not the way we want to start off,” Dzamko said of the summer boating season.

Dzamko said the teen was swimming near Rock Island in water that’s up to 30 feet deep. Police have yet to identify him, but detectives have interviewed his friends, Dzamko told the newspaper.

The water temperature in Candlewood Lake was roughly 60 degrees at the time.

A man who was boating nearby with his family told WFSB that he heard three teenagers scream for help.

“And they were saying it was their friend who had a panic attack or anxiety attack while swimming and went under,” Dr. Ralph Tremaglio told the station.

Three of the four teens safely reached Rock Island, Tremaglio said.

“We were stunned,” he told the station. “We didn’t know what to do. Some younger guys borrowed life jackets from us and other boats just started diving.”

Police told the station that the missing teen is from Milford.