The catastrophic traffic accident involved a tourist bus traveling from New York to Ohio, ABC quoted US officials as saying.
At least five people were killed and 60 injured. The accident occurred at around 3:30 a.m. on January 5 on the highway near New Stanton, nearly 60km southeast of Pittsburgh.
The weather could be a factor in the accident, authorities said. At the time of the accident, the temperature was at frozen levels, fog and occasional snow.
The accident caused the expressway to close in both directions. At least 25 victims, aged 7 to 52, are being treated at Excela Health Frick Hospital in Mt.Pleasant, Pennsylvania. Two of the victims were transferred to the hospital's injury center.
Nine of the total number of victims hospitalized are under the age of 18, according to the leader of Excela Health Hospital.
Aerial images from the scene show the tourist bus overturned, surrounded by 3 trucks, including a cargo truck and packages dumped on the road.
The series of car crashes occurred just two weeks after more than 50 people were injured in the accident involving 69 vehicles near Williamsburg, Virginia, USA. Dense fog and a slippery expressway due to ice caused the accident on December 22.
