Updated

Authorities say a mail carrier has died after being pinned by a U.S. Postal Service vehicle that rolled down a driveway in Michigan.

State police say 56-year-old Tracy Sylo of Pinckney died Wednesday in Washtenaw County's Lyndon Township while delivering a package to a home.

Police say the mail truck was parked at the top of the driveway of a home that sits on a hill about 45 miles west of Detroit. The vehicle rolled and struck the mail carrier, pinning her between the vehicle and a metal guardrail.

A statement from police says Sylo died at the scene. The death is under investigation and police are working to determine why the truck rolled.