On Dec. 11, 1990, an unusual weather event caused one the deadliest crashes in Tennessee history when a dense fog fell near Calhoun, Tennessee.

The 99-vehicle pileup caused 12 deaths and 42 injuries, according to the Chattanooga Times Free Press. It began in the southbound lane of Interstate 75 when an unusually dense fog fell rapidly, reducing visibility to almost nothing in a very short time. 

According to the official highway accident report from the National Transportation Safety Board, the fog came from settling ponds and steam emitted from the Bowater paper mill nearby. The weather forecast for the day was sunny and mild with temperatures in the 60s and no evidence of fog on its way.

The fog fell so fast witnesses said it was like throwing a blanket onto a windshield, said the newspaper article. Bradley County Deputy Bill Dyer was the first on the scene and originally couldn’t even find the crash because the fog was so dense. He drove so far that he reached an area outside of his jurisdiction and had to turn around, according to Chattanooga’s News Channel 9.

Eventually, Dyer found the crash when a man walked out of the fog pleading for help. 

“A man stumbled out of the fog towards my police cruiser,” Dyer recounted. “His face was bloody and he was about to collapse. As I got out to help him, I started hearing the sound of metal crunching, just one right after the other. It was coming from north of the bridge over the freeway, but I couldn’t see anything. I stabilized the victim and started running toward the sounds I was hearing.”

“And then,” he says, “I heard the screams.”

Within those 99 vehicles that continued to pile up over the course of hours that day were numerous 18-wheelers. One woman, Becky Isbill, was able to escape her damaged car just before another vehicle sideswiped her vehicle and slammed into the back of a wrecked 18-wheeler. Quickly after that, another 18-wheeler crashed into the back of the car, killing two people.

Heart-breaking stories similar to Isbill’s piled up like the wreckage on the interstate.

In the days after the tragedy, the gruesome accident made an impact on safety protocols in Tennessee. After the wreckage was cleaned up, which took days, the Tennessee Department of Transportation installed a system to warn drivers with flashing lights and lowered speed limits when fog is detected. The system is still in place today. Advancements have been added to the system with HD cameras that have 360-degree rotation and zoom capabilities. That $6.8 million upgrade came in 2006, according to the Chattanooga Times Free Press

Many of the victims have experienced post-traumatic stress symptoms and pray nothing like this ever happens again. Authorities hope so too and created a protocol to shut down the highway if fog like that ever appears again. Today, these improvements are working to save lives and create a safer highway experience.

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