POTTSVILLE, Pa.—A stretch of an interstate highway in Pennsylvania remained shuttered Tuesday, a day after at least three people were killed and more than a dozen others injured when tractor-trailers and other vehicles lost control and slammed into each other during a snow squall. Interstate 81 north remained closed early Tuesday morning following the wreck Monday morning amid poor visibility that involved between 40 and 60 vehicles, authorities and published reports say. The crash Monday on Interstate 81 was captured in videos posted on social media that showed drivers and passengers lining the snowy road and jumping out of the way as the cascade of crashes unfolded. The north and southbound lanes of the highway were closed for several hours after the accident, but the southbound side reopened around 6:30 p.m. Monday. It was not known when the northbound side would reopen. Numerous vehicles remained on the roadway in the …