A chain-reaction crash involving a tour bus, three tractor-trailers and a passenger car killed five people and injured about 60 others on the Pennsylvania Turnpike near Pittsburgh early on Sunday, state police said.
National Transportation Safety Board (NTSB) investigators began arriving hours later in Mount Pleasant Township, about 40 miles (64 km) southeast of Pittsburgh, to determine the cause of the pre-dawn pileup.
The accident forced the closure of an 86-mile (138-km) stretch of the turnpike, a major east-west highway across the state, in both directions between the exits for New Stanton and Breezewood, adding to post-holiday travel woes in the region.
The highway was reopened about 16 hours after the crash, state police said.
The tour bus was headed downhill when it swerved into an embankment at a bend in the road and rolled over on its side, state police spokesman Stephen Limani told a news conference hours later.