MINNEAPOLIS (WCCO) — Authorities in Cass County are investigating the death of a man, who was attacked by a bear and later died of unrelated causes.

According to Cass County Sheriff Tom Burch, the office received a report on July 8 at 10:49 p.m. of a medical situation in Ponto Lake Township, located near Lake Ada in rural Pine River.

There, a 70-year-old man was complaining of stomach pain. He was treated on scene and airlifted to Fargo Hospital.

An investigation revealed that two days earlier, the victim was attempting to scare a bear away from his yard when he was charged by another bear. He was thrown into the air and landed on the ground. However, there were no external visible injuries to the victim from the incident.

On July 9, the sheriff’s office was told that the victim died at the hospital. A preliminary autopsy found that the bear incident did not cause the death of the victim, and there were no injuries or wounds discovered during the autopsy.

The death remains under investigation.