Updated on February 13, 2021 at 12:03 pm NBCUniversal, Inc. What to Know Six people killed in massive pileup; 65 people treated at hospitals for injuries including 36 who were taken by ambulance Officials estimate at least 133 vehicles were involved in the pileups Crashes occurred in the southbound, interior North Texas Express toll lanes of Interstate 35W At least six people have died and dozens more were injured in a massive pileup involving at least 133 vehicles on the North Texas Express toll lanes in Fort Worth early Thursday morning that occurred after overnight sleet made for treacherous driving conditions. All southbound lanes of Interstate 35W north of downtown, including the interior toll lanes where the crashes took place, remained closed through the day and overnight as dozens of firefighters and other first responders continued to work in bitterly cold temperatures to clear the damaged vehicles from the highway.