A wreck between three semi trucks caused a spill of hazardous chemicals on Interstate 65 on Wednesday, forcing a complete shut down of a portion of the highway due to an explosion risk.

The accident happened on January 10th at approximately 4:30 a.m. in Seymour, Indiana.

According to The Republic, a tractor trailer was traveling south on I-65 when it rear-ended two semi trucks stopped for traffic from a previous wreck, causing one of the big rigs to leak several of the hazardous chemicals it was hauling.

Only one passenger in one of the semi trucks suffered minor injuries in the wreck.

Initially, officials believed that the chemical spill could be contained, and allowed traffic to pass by in one lane of southbound I-65, but complications from the cleanup soon arose, forcing the shut down of I-65 in both directions from mile marker 41 to 50.

Eventually, the truck caught fire, posing what police called an “explosion risk” and prompting officials to issue a non-mandatory evacuation of the surrounding areas.

Indiana State Trooper Seth Davidson says that the truck was hauling four hazardous chemicals, two corrosion, one oxidizer and one with acid.

“The chemicals spilled and mixed,” he explained.

As of 1:43 p.m., both sides of I-65 were shut down between mile marker 41 and 50, and officials were allowing the fire to burn itself out. The roadway is expected to remain closed, with a suggested evacuation order in place, for the next four hours.