Residents were ordered to evacuate their homes after a chemical fire broke out Monday morning at the Chemtool Inc. plant in Rockton, Illinois.The city fire department ordered a mandatory evacuation for all residents and businesses in a one-mile radius of the plant, police said in a message on Twitter.

WREX reported that city Fire Chief Kirk Wilson said late Monday morning that the blaze does not pose an immediate danger to the community. The fire department will let the fire burn itself out to avoid environmental issues, WREX reported.Wilson said the 70 employees at the factory were able to get out safely. When fire crews arrived, the flames were through the roof and clouds of smoke filled the sky.CNN affiliate WIFR said one firefighter was injured. No other details were immediately available.At least 40 agencies and 150 fire personnel responded to the blaze, Wilson told WREX.

Explosion sounded like “a decent-sized firework”

Residents of Rockton, located about 15 miles north of Rockford near the state line with Wisconsin, reported hearing a series of explosions.”My family and I live in the evacuation zone,” Thomas Rollette told CNN. “We heard the explosions this morning and decided to check outside maybe five minutes afterwards when our dogs wouldn’t calm down. By that point the smoke was already filling the sky.”

He said the first explosion sounded “like somebody lit off a decent-sized firework.””It wasn’t until more and louder explosions came that I even thought something was going on. Seeing the wall of smoke outside just confirmed it for me, and pretty soon after they were telling the nearby residents to evacuate.”