The autopsy performed on 66-year-old Jeffrey Wolk, who was found dead in Lake Thunderbird on Sunday morning, revealed that the man suffered a brain aneurysm.
Monday's autopsy was scheduled to help determine how Wolk may have ended up in the water. He was found floating in the water by two people who were fishing on the lake.
Wolk lived in a residence at the development located east of St. Clair.
The Franklin County Sheriff's Office, deputies and emergency personnel were dispatched to the lake at about 10:40 a.m. after the two individuals stated they saw something floating in the water that looked like a body.
The two people said they regularly go fishing on the lake on Sunday mornings and they spotted the body as they entered a cove. They contacted the sheriff's office at that time.
Relatives stated Wolk did have a medical history.