WEXFORD, Pa. - A jackknifed tractor-trailer snarled traffic on Interstate 79 South Tuesday morning between the Warrendale and Wexford exits.
Officials said the tractor-trailer jackknifed just after 6 a.m. and ended up partially in the center median and partially blocking the left lane.
There were no reports of injuries, and crews said drivers experienced delays for several hours.
Investigators said delays caused by the tractor-trailer accident led to a several-car pileup on the Pennsylvania Turnpike near the Cranberry exit.
Three cars sustained major damage and traffic backed up for miles, officials said.