NTSB: I-35W in Fort Worth was treated with brine solution before deadly 135-car pileup

The southbound lanes of Interstate 35W were treated with a brine solution before a deadly 135-car pileup during February’s winter storm, according to a preliminary investigation.

The National Transportation Safety Board released its preliminary report on the crash Wednesday.

The massive pileup happened on the morning of Feb. 11 on the southbound side of I-35W near Northside Drive, north of downtown.

RELATED: 6 dead, dozens injured in I-35W pileup in Fort Worth involving 135 vehicles

Drivers who were reportedly traveling at a high rate of speed ventured onto slick roads coated with a thin sheet of ice from freezing rain that had fallen overnight and into the early morning hours.

Cars, trucks and 18-wheelers collided one after another for a crash scene that stretched for nearly a mile. Six people lost their lives and dozens were injured.

RELATED: Victims identified, survivors recall terrifying scene as cars piled up in Fort Worth

The NTSB’s report states two of the people who were killed had gotten out of their vehicles and were struck on the road. The other four were fatally injured while inside their vehicles.  

A total of 36 people were treated at area hospitals for their injuries, the report states. That number is lower than the 60 initially reported.

"All you could hear was metal crunching and cars hitting cars," said Nick Stevenson, crash victim. "When I came up over the hill it was just a mess and I didn’t have anywhere to go on the road, it was just ice once we topped the hill. I was trying to slow down, trying to get to the wall."

Stevenson says he didn’t have any time to react. The crash crushed his truck and leaving him trapped for more than two hours.

"My neck was hurting, my shoulders and neck were all burning and after the semi hit me, my back window broke out so it was very cold," he said.

The terrible tragedy prompted several lawmakers and political activists to question whether the road was properly treated for ice before the freeze.

RELATED: Lawmakers looking for answers about deadly Fort Worth pileup

State Rep. Ramon Romero, a Democrat whose district covers most of Fort Worth, blamed the private company that was hired to treat the lanes and argued it didn’t uphold its end of the deal.

NTSB investigators determined that in the days leading up to the crash, NTE Mobility Partners Segments 3 reported it had pre-treated the roads with an Ice Slicer NM brine solution. That solution was applied to the two southbound lanes in the area of the crash.

"The roads were fine up until 28th street, and then after that, where the wreck occurred was a bridge and it was like there was no treatment whatsoever, even the first responders were having to throw sand down just so you could stand up, it was just a sheet of ice," Stevenson said.

Road signs managed by the same company were displaying a warning message about icy conditions at the time of the crash, the report states.

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The NTSB said it is still conducting a more focused investigation into road treatment strategies used to address freezing conditions.

NTE Mobility Partners is helping with that investigation, along with the Texas Department of Transportation, the Fort Worth police and fire departments and other agencies.

"Somebody needs to be held accountable and they need to do their jobs," Stevenson said.