LEE TOWNSHIP, Mich. — Authorities say a 76-year-old man has died and his 16-year-old grandson was injured after the helicopter they were riding in crashed in mid-Michigan.

The Midland County sheriff’s department says Paul Pangborn of Midland was piloting the helicopter on Sunday afternoon when it went down in a field in Lee Township, about 100 miles (161 kilometers) northwest of Detroit. The department says Pangborn was pronounced dead at a hospital.

Sheriff Scott Stephenson tells WJRT-TV that Pangborn had flown to his grandson’s birthday party and picked him up before the crash.

His grandson was treated at a hospital for what were described as minor injuries before being released.

The cause of the crash is under investigation. The sheriff’s department says the helicopter was flying when it rotated and slowly went down.