A portion of a major Pennsylvania highway was closed Monday after as many as 60 vehicles were involved in a fiery crash due to snow squalls, according to Pennsylvania State Police. The crash occurred on Interstate 81 at about 10:30 a.m. in Schuylkill County near Minersville, about 100 miles northwest of Philadelphia, John Blickley of the county's emergency management office, told USA TODAY. Blickley said he was not aware of any fatalities, but about 20 patients were sent to area hospitals with injuries. 📸: @apnews The National Weather Service office in State College warned of snow squalls in central Pennsylvania and advised drivers to stay alert. “The squalls will quickly reduce the visibility to under one-half of a mile and coat the roads with snow,” forecasters said, urging drivers to get off the road if possible or turn on hazard lights “and gradually slow down to avoid a chain reaction vehicular accident.” Footage uploaded to social media showed an out-of-control tractor-trailer smash into a large dump truck, turning it nearly 180 degrees. Another large truck spewed black smoke and orange flames into the air and an SUV struck a passenger car sending the sedan spinning, narrowly missing its driver who stood on the shoulder of the highway shrouded in snow and fog.