SOUTH BEND, Ind. (AP) _ Authorities say a South Bend man has died after a tractor that he was using to do yard work turned over on top of him.

St. Joseph County Police Lt. Bill Redman says 55-year-old Michael Michaels was pronounced dead at the scene outside his home Sunday afternoon. According to authorities, Michaels was moving a tree with the tractor when it overturned.

Police say a person helping Michaels panicked, but a passerby called 911. Redman says officers already in the area were on the scene within minutes, and they and the passerby moved the tractor off Michaels using their hands.

According to Redman, officers tried saving Michaels, but authorities determined he was dead when paramedics and fire department responders arrived.

Authorities are investigating Michaels' death as an accident.