The road closed shortly after the crash was reported around 4:40 p.m. on Apr. 5, according to the Pennsylvania Department of Transportation.
The portion of the highway that has shut down is between Granite Station and Hoffman roads in Straban Township, according to a release by Pennsylvania state Trooper Megan Ammerman.
The highway "will be closed for an extended period of time," Ammerman says.
Drivers are asked to avoid the area and a detour has been put in place.
The exact number of cars and persons involved is unknown.
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