Six people were killed in a massive pileup involving more than 100 vehicles on a Missouri highway Thursday morning, authorities said.

The deadly chain reaction crash on Interstate 57 near Charleston unfolded after a driver hit their brakes due to foggy conditions in the area, officials told KFVS.

First responders from Missouri, Illinois, and Kentucky raced to the scene of the “mass casualty motor vehicle collision” involving “over 135 vehicles,” the Scott City Fire Department wrote on Facebook.

“When we got the call about 8 a.m., and as we approached the interstate it was a very thick fog,” Charleston Department of Public Safety Director Robert Hearnes reportedly said.

“You couldn’t … visibility was less than 50 feet. And so the traffic had already backed up, but we had multiple, multiple accidents on both sides of the interstate.”

A mobile morgue had been set up in a Charleston funeral home, Mississippi County Coroner Terry Parker told the local station, as he confirmed a sixth fatality.

Other injured people were treated on scene and at local hospitals, including several first responders, Parker reportedly said.

“Only in one of, one of the worse war movies, or a Chicago or St. Louis fire, something we’d maybe see on the news in a large city, but nothing of this nature in our area,” he told the station.

The names of the victims had not yet been released because not all of their families had been notified, authorities said.