MINNETONKA — The family of an 8-year-old girl who died after a medical emergency on Lake Minnetonka said she was killed by carbon monoxide poisoning.

Emergency crews were called shortly before 5 p.m. Sunday to a dock on Wayzata Bay, where they found Sophia Baechler of Edina unresponsive. She was taken to Hennepin County Medical Center, where she died.

Sophia was a second grader at Concord Elementary School in Edina. Her parents informed school staff Monday morning about the cause of her death.

Principal Tony Washington sent a letter to parents Monday saying the girl’s parents informed him that she died of carbon monoxide poisoning.

The Hennepin County Sheriff’s Office is investigating the incident.