BREAKING: ‘Mass casualty incident’ unfolding on Texas highway as more than 100 cars pile up because of icy roadways, trapping people in vehicles — UPDATED

A rescue operation is under way on Thursday after more than an estimated 100 cars piled up on a Texas highway between Fort Worth and Dallas after sleet turned the roadways into sheets of ice, according to reports.

What are the details?

According to the Daily Mail, the crash site runs more than one and a half miles long, and first responders are referring to the catastrophe as a “mass casualty incident.”

Early Thursday morning, the Fort Worth Fire Department tweeted, “MCI alert. 1601 N Freeway. Multiple vehicles involved. Multiple people trapped. More details to follow. PIO responding.”

First responders are still attempting to access many of the vehicles, but are reportedly having difficulties due to the icy roads.

Twitter user Jason McLaughlin shared footage of the mass crash, captioning it, “Here at the scene in North Fort Worth in one of the worse [sic] disasters I have ever seen in this area. Pray. Pray hard. 100+ of vehicles.”

KDFW-TV reported that there have been three confirmed deaths at the time of this writing.

First responders said that there were also “multiple” 18-wheelers among the wreckage.

According to KDFW, the horrific incident has closed both northbound and southbound traffic on I-35, as first responders continue to arrive on the scene.

This is a developing story and will be updated as events warrant.