PHILADELPHIA (AP) — A Greyhound bus struck a tractor-trailer early Wednesday on Interstate 80 in central Pennsylvania, killing a woman, critically injuring four other people and sending dozens to the hospital, authorities said.

Trooper Matthew Burrows of the state police barracks in Milton said the bus was extensively damaged when it hit the rear end of a flatbed trailer that was hauling garbage at about 1:30 a.m. in the westbound lanes of I-80 in Union County’s White Deer Township.

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Forty-five of the 50 people aboard the bus, including the driver, were taken to five hospitals, Greyhound spokeswoman Alexandra Pedrini said. The bus was heading from New York City to Cleveland, and the driver had been with the company for more than 12 years, she said.

The driver of the tractor-trailer, Akos Gubica, 36, of New Jersey, told The (Sunbury) Daily Item that his rig was struck from behind by the bus. Pedrini declined to comment on that, saying the company was cooperating with authorities in their investigation and was conducting an internal probe.

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Geisinger Medical Center said four of the 17 patients it received were in critical condition, with two listed as serious and 11 fair. Evangelical Community Hospital in Lewisburg said it had received 14 people but was unable to immediately provide their conditions.

Lock Haven Hospital spokesman Jeff Johns said one of the three patients the hospital received was transferred, another was admitted and the third was treated and released. Tracie Witter of Susquehanna Health Systems said 10 people were treated at Muncy Valley Hospital and released while five were treated at Williamsport Regional Medical Center and released.

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