Garrett, IN- Carbon monoxide killed a Garrett girl who died after a boating accident, according to autopsy results released Tuesday afternoon.

Jesslynn S. Gustin, 8, died shortly after noon Monday at Parkview Hospital in Fort Wayne, according to the Allen County coroner’s office.

Coroner E. Jon Brandenberger, M.D., conducted an autopsy Tuesday afternoon. He then released his preliminary finding, ruling that the girl’s death is accidental as a result of “hypoxic encephalopathy due to carbon monoxide poisoning.” Hypoxic encephalopathy refers to a lack of oxygen to the brain.

The fatal incident began when Miss Gustin fell off the back of a speedboat Sunday in Huntington County, authorities said.

The girl was sitting on a swim platform at the back of a boat that was moving slowly across Roush Lake, just before 4:30 p.m. Sunday. She became unconscious and slipped into the water, said Indiana Conservation Officer Rodney Clear.

A family member pulled her from the water within one minute, and a Samaritan Helicopter flew her to Parkview Hospital, Clear said.

“It is believed that carbon monoxide from the motor might have been a reason for the child becoming unconscious and slipping into the water,” said Clear, public information officer for conservation officers in northeast Indiana.

Brandenberger’s statement said the death remains under investigation by the Indiana Department of Natural Resources and the Allen County Coroner’s Office,

Roush Lake, also known as Huntington Reservoir, is about three miles southeast of the city of Huntington.