As an orange fog began billowing from the front of a wrecked semitrailer carrying hazardous materials Wednesday on Interstate 65 south of Seymour, those involved in the cleanup knew the situation had taken a turn for the worse.

An hour after reporting that one of the southbound lanes of the interstate had reopened near the 43-mile marker, Indiana State Police Sgt. Stephen Wheeles said complications from the cleanup forced the re-closure of both lanes.

Thirty minutes later, police closed the northbound lanes until 4 p.m. as some of the five different hazardous chemicals being hauled in the trailer from Chicago to Jacksonville, Florida, caught fire. Two other semitrailers involved in the wreck already had been hauled away.

A mixture of the chemicals being hauled, including medical cleaning supplies, printer ink, weed killer, pool chemicals and other acids, is thought to be the cause of the fire, Senior Trooper Seth Davidson said. Indiana Spill Response of Anderson and Midwest Environmental Services of Brownstown were called to clean up the chemicals.

Davidson said crews discontinued unloading when the orange fog appeared.

“Whatever happened in that trailer caused an orange fog, which is a chemical reaction, and when that fog got super-hot and heated, that’s when it combusted into the fire,” he said.

Shortly thereafter, Indiana State Police began alerting residents and businesses within a half-square-mile fringe of a voluntary evacuation.

Some of the chemicals were stored in 55-gallon steel drums, while others were in five-gallon pails and buckets, said Davidson, who is a commercial vehicle officer responsible for inspecting the truck. It’s unclear how many drums and buckets were on the trailer because the shipping information burned.

Davidson said the chemicals can be hauled together so long as they’re properly secured.

“There wasn’t a problem with them being on the same trailer,” he said.

Whether the chemicals were properly secured is something that won’t be known because of the blaze, he said.

“We have no clear if and how properly the load was secured,” Davidson said, adding the stored chemicals went forward in the trailer after the wreck. “That doesn’t mean it was not secured or not properly. We will never know because of the fire.”

That fire would burn for about four hours, leaving cleanup crews with the burned-out husk of the semitrailer to clean up. The Environmental Protection Agency advised first responders not to attempt to extinguish the blaze with water due to environmental concerns.

A box truck that was being used to store chemicals being unloaded from the semitrailer also was consumed by the fire. The blaze also left charred asphalt, later repaired by the Indiana Department of Transportation. The southbound lanes reopened about 9 p.m.

No one was injured in the fire, but a passenger in the semitrailer that burned sustained non-life-threatening injuries in the crash that led to the fire.

That collision, reported at 4:37 a.m. Wednesday, began when a 2017 Freightliner driven by Uche J. Okpeh, 30, of Jacksonville rear-ended a semitrailer driven by Vitali Kriuchkov, 34, of Orlando, that was stopped in the right lane. The collision pushed Kriuchkov’s truck into a third semitrailer driven by Bobby L. Brand, 46, of Gadsden, Alabama.

The passenger in Okpeh’s truck, Senesie Kyateh, 39, of Jacksonville, was treated and taken to Scott Memorial Hospital in Scottsburg and released before the fire began at about noon, Davidson said.

The southbound lanes were reopened at 9 p.m.

The incident was overseen through a coordinated effort between the Indiana State Fire Marshal’s Office and the Indiana Department of Environmental Management.

The investigation is ongoing, and it is not known whether charges or citations will be issued, Wheeles said.

[sc:pullout-title pullout-title=”At a glance” ][sc:pullout-text-begin]

The following is a list of hazardous materials being carried on a semitrailer that burned on Wednesday after it was involved in wreck near the 43-mile-marker on Interstate 65.

UN3164 These are pressurized pneumatic containers which contain a non flammable gas probably sometime used in vehicles

UN1760 This is a corrosive liquid this is probably weed killer

UN1719 This is a caustic alkali liquid (this is an acid of some kind)

UN3085 This is Dantobrom this is an acid used as a pool chemical

UN3265 This is Glutaradehyde. It is an acid used to disinfect in heath care industry and many other uses.

[sc:pullout-text-end]