A Midvale man was in serious but stable condition Thursday morning after the front dual wheels of a semitrailer truck on which he was performing maintenance ran over him.

William Hewitt, 18, was underneath the semi at Swift Transportation Co., 2900 W. Parkway Blvd., when a driver got into the truck and began pulling away at 3:40 p.m. It is unknown if the driver knew Hewitt was beneath the vehicle, said Lt. Lynn Hanson of the West Valley City Police Department.Hewitt was transported to University Hospital, where he is in an intensive care unit.

The truck was licensed in Oklahoma and belongs to the transportation company.