NEWRY – Oxford County police are investigating Sunday’s death of a New Hampshire snowboarder who fell Saturday morning on a trail at Sunday River Ski Resort and was airlifted to a Lewiston hospital.

Deputy Chancey Libby said late Tuesday afternoon that he began investigating the accident when he was notified, 24 hours after it happened.

Libby said that Shannon Kiernan, 28, a teacher at Winnacunnet High School in Hampton, N.H., apparently fell on her head at 11 a.m. while riding down Obsession, an advanced ski trail. She was wearing a helmet.

Kiernan was flown to Central Maine Medical Center where she was pronounced dead on Sunday.

“I was told she was an avid snowboarder,” he said.

Despite nearly completing the investigation by Tuesday, Libby would not yet release details. He said he is awaiting autopsy results from the Medical Examiner’s office in Augusta.