At least six people have died from a massive freeway pileup on Thursday in Fort Worth, Texas, according to Fort Worth police.

Reports say the first crash on highway I-35 occurred around 6 a.m. A total of 135 vehicles were involved in the accident.

Local service Med Star transported at least 65 people for treatment at local hospitals, The Dallas Morning News reported. Some were trapped in their cars.

Numerous patients were treated and released on scene, police said, while others left the crash site on their own but later went to hospitals.

A large number of victims were health care workers, found wearing their work scrubs and hospital badges, according to reports.

All victims assessed on the scene were adults.

Fort Worth police said ice from freezing rain was likely a factor.

Some lawmakers questioned if the area had been salted or sanded before the crash, with some reports indicating that the roads had not been prepared.

State Rep. Ramon Romero Jr. said his office would open an investigation into the allegations.

Five of the six victims have been identified.

The Tarrant County Medical Examiner identified four of the five victims as being from Texas: Tiffany Louann Gerred, 34, of Northlake; Aaron Luke Watson, 45, of Fort Worth; Christopher Ray Vardy, 49, of Boyd; and Michael Henry Wells, 47, of Justin.

The fifth, William Darrell Williams, 54, was from Pahoa, Hawaii.

Our thoughts and prayers go out to all the victims involved in this tragedy, as well as the grieving families.