▶ Watch Video: Massive chemical plant explosion prompts evacuations in Illinois

Rockton, Illinois — Residents are under evacuation orders after an early morning explosion at a Chemtool plant sent a huge ball of flames and thick black smoke into the air. The ball of flames could be seen as far as 100 miles away, and the explosion was so powerful that debris fell onto homes in nearby towns. 

The explosion at the northern Illinois plant occurred shortly after 7 a.m. local time. Authorities are allowing the fire to burn itself out — which could take several days — instead of trying to extinguish it with more water, the city’s fire chief said. 

“We felt it was in our best interest to let this product burn off,” Rockton fire chief Kirk Wilson said Monday. 

Firefighters from Northern Illinois and Southern Wisconsin battle an industrial fire at Chemtool Inc. on June 14, 2021, in Rockton, Illinois. The chemical fire at the plant which produces lubricants, grease products and other fluids has prompted local evacuations.

Scott Olson / Getty Images

Investigators aren’t sure how the fire, which occurred at a company that said it’s the largest manufacturer of grease products in the country, originally started. About 70 employees working at the time were safely evacuated. Businesses and residents within a one-mile radius were also evacuated. 

“I wasn’t that alarmed until more and more explosions started occurring, and we could now see lit fire material raining down,” one evacuated resident said.   

Investigators said the air quality is safe for now. “Everyone can see the large plume of smoke … But I assure you that there is no danger at ground level at the plant,” Wilson said. 

Governor J.B. Pritzker sent in members of the Illinois National Guard, CBS Chicago reported

“I am monitoring this situation closely and will make all resources available to the surrounding communities as we work to keep people safe,” Pritzker said in a news release. “Teams from multiple state agencies are on the ground and coordinating closely with local authorities and we will continue to make additional information available as soon we have it.”