Multiple people were killed in a major crash involving a tour bus and three semi-trucks on the Pennsylvania Turnpike early Sunday in the western part of the state that left dozens injured, according to officials.

The crash happened around 3:30 a.m. Sunday in the highway's westbound lanes in Mount Pleasant Township, located about 40 miles southeast of downtown Pittsburgh.

Pennsylvania Turnpike spokesman Carl DeFebo confirmed fatalities on Twittersaying a "prolonged closure" of the turnpike is likely. DeFebo added the Westmoreland County coroner confirmed five fatalities.

Pennsylvania State Police said the tour bus was traveling westbound on the highway on a downhill curve when it struck an embankment. Commercial vehicles traveling behind then struck the tour bus, according to state police.

A total of six vehicles were involved in the crash, including a tour bus, three semi-trucks loaded with parcels and one private passenger vehicle, according to police.

State police said that a total of 39 people were transported to area hospitals, including 28 sent to Frick Hospital in Mount Pleasant and 11 transported to Forbes Hospital in Monroeville.

Images from the scene showed mangled wreckage on the highway. A tour bus could be seen flipped on its side as a result of the crash.

Angela Maynard, a tractor-trailer driver from Kentucky, told the Pittsburgh Tribune-Review she was traveling eastbound with her co-driver on the turnpike around 3:30 a.m. when they came across the crash.

“It was horrible,” she said.

Maynard told the newspaper she saw someone laying on the ground, while another person was trapped in their truck.

“I walked toward the scene and saw one of the truck drivers laying near the barrier. I tried to keep him occupied, keep talking, until medical help arrived," Maynard told the Tribune-Review. "He was in bad shape. He was floating in and out of consciousness.” Read more at FOX News