CHESWICK, Pa. (AP) - A tractor-trailer carrying advertising circulars overturned on the Pennsylvania Turnpike and caught fire, closing a stretch of highway for hours.

The truck crashed at around 3:30 a.m. Monday between the Butler Valley and Allegheny Valley exits, blocking three lanes. All the lanes reopened by 9 a.m.Postal spokesman Tad Kelley says the truck was heading to four U.S. Postal Service facilities in Maryland, though it is owned by a private hauling firm. The trucking company and the advertising company will deal with the lost cargo.The Postal Service said in a statement released to KDKA-TV that no one was hurt in the crash, but most of the advertising circulars were damaged.