Emergency dispatchers in Mercer County say the initial crash was reported about noon Saturday near the Greenville-Sandy Lake exit. The southbound lanes, where the crash occurred, have been closed from Exit 147A near Meadville to the Greenville-Sandy Lake Exit 130. The northbound lanes are closed from Exit 130 to Exit 141 at Geneva.
Although some injured people have been taken from the scene, dispatchers say no fatalities or serious injuries have been reported.
PennDOT officials and dispatchers estimate 20 to 30 vehicles may be involved. It was not immediately clear when the interstate would reopen.
Traffic is being detoured to U.S. Route 19, which runs roughly parallel to I-79, the main north-south highway in western Pennsylvania.
