Investigators have determined the cause of death of a 28-year-old Sebago woman who was found in a car submerged in the Ossipee River in Parsonsfield in February.

Sarah McCarthy’s cause of death was drowning with hypothermia and the manner of death was accidental, the Cumberland County Sheriff’s Office announced Wednesday. McCarthy was found in her car in the river two days after she was last seen, in Cornish on Feb. 14.

Toxicology testing done by the state Medical Examiner’s Office showed McCarthy had a blood alcohol level of .21 percent and marijuana and amphetamines were detected in her system, according to Capt. Don Foss.

McCarthy was last seen at Fairgrounds Pizza & Pub in Cornish, where she worked as a waitress and bartender. She had planned to meet a friend in Conway, New Hampshire, after her shift.

McCarthy had telephone contact with family and friends shortly after leaving work, and “she sounded very disoriented and claimed she did not know where she was,” Foss said. She also reported being lost and cold.

A passerby spotted McCarthy’s vehicle submerged in the river near the intersection of Route 25 and Elm Street on the afternoon of Feb. 16.

McCarthy’s disappearance was investigated by the Cumberland County Sheriff’s Office, while the York County Sheriff’s Office investigated the crash.

McCarthy, who went by “Sarie,” grew up in Sebago and moved to South Carolina after college. She had moved home to Maine to return to school to be a nurse, her friends and family said earlier this year.