The death of a man who was found unresponsive in his car after it left the road in Fridley early Thursday is under investigation, authorities say.

Fridley police received a 911 call to check on a vehicle that appeared to have left the roadway near Hwy. 65, just north of Interstate 694, at 3:46 a.m. Thursday, according to a release from the Anoka County Sheriff’s Office. Officers found the 51-year-old St. Anthony man unresponsive in the car. CPR and other lifesaving efforts were attempted, but the man died.

The Midwest Medical Examiner’s Office will conduct an autopsy to determine the cause of death. The man’s name has not yet been released.

Fridley police, the Anoka County Sheriff’s Office and the Minnesota State Patrol are investigating.