At least six people were killed and 65 were injured in a massive freeway accident in Fort Worth, Texas, involving 133 vehicles Thursday morning, CNN reported Friday, citing Fort Worth police.

Fort Worth Fire department rescue personnel said several people were trapped in their vehicles on I-35 interstate freeway. Authorities said the pileup was likely caused by poor road conditions after winter storms across the Dallas-Fort Worth area of Texas.

Numerous patients were treated on scene, police said, while others left the crash site on their own but later went to hospitals. The crash was reported around 6 a.m. CT and stretched about a mile.

According to Dallas Police Department spokesperson Tamika Dameron, more than 300 vehicular mishaps were reported overnight. 

Also wounded were four police officers, three of whom were involved in the pileup as they were heading for duty. One was hurt while working at the crash site, police said.

"Right now, what Fort Worth needs most is your prayers, for the families, the wounded, and the first responders," Fort Worth Mayor Betsy Price said in a tweet quoted by ABC News.

More than 80 police units responded to the crash, including personnel from the Special Events unit, formed to respond to large-scale accidents, Fort Worth Fire Chief Jim Davis said in during a news briefing.

Matt Zavadsky, spokesperson for the MedStar ambulance service, said 13 ambulances were dispatched to the scene along with critical care paramedics.

The area was under a winter weather advisory until Thursday evening because of heavy accumulation of ice, which causes very slippery sidewalks, roads and bridges, authorities said.

It's been decades since three of the deadliest vehicular accidents in U.S. history, according to Good Morning America.

On May 14, 1988, a drunk driver killed 27 people near Carrollton, Kentucky.

On Dec. 11, 1990, 12 people were killed because of fog on I-75 freeway in Calhoun, Tennessee.

On Nov. 29, 1991, a heavy dust storm led to a pileup on Interstate I-5 near Coalinga, California, killing 17 people.