Various videos surfaced Thursday showing the details of a massive traffic pileup in Fort Worth that’s trapped several people and left at least five dead.

Freezing rain and cold temperatures led the National Weather Service to issue a winter weather advisory for parts of Texas on Thursday. Treacherous road conditions led to a pileup of up to 100 vehicles on Interstate-35W in Fort Worth.

[Warning: Videos below may be disturbing to some readers.]

Mike Drivdahl, a spokesperson for the Fort Worth Fire Department, was quoted by the Dallas-Fort Worth affiliate for CBS that the situation was still very fluid.

“We are going vehicle, by vehicle, to make sure that anybody that is still trapped in their vehicle has been extricated, if possible,” he said. “There’s a lot of vehicles to go through.”

KHOU-11 reports the chain-reaction crash began at around 6 a.m. local time, reportedly because the freezing rain had created pockets of dangerous black ice on the roadway. At least 14 ambulances were sent out in the first response after the incident was declared a “mass casualty” event by local authorities.

“A [MedStar] spokesperson says the number of patients is growing by the minute, right now 20-30, some in critical condition,” WFAA reporter Eric Alvarez said from his Twitter account. “At least 50 vehicles involved. Some are wedged under other vehicles.”

The National Weather Service in Fort Worth said from its Twitter account that road conditions were extremely hazardous.

“We can't stress enough that road conditions could go from good to dangerous within blocks,” it stated.

Dangerous weather conditions are expected through the weekend. The weather service warns that wind chills could dip below zero degrees Fahrenheit by Saturday and that conditions could last through early next week. Much of the nation is in the grips of a polar vortex that brings in a rush of arctic air from the extreme north.

Police Sirens Above is a representational image. Photo: Pixabay