At least 11 employees were taken to hospitals and residents were urged to shelter in place on Tuesday after an explosion at a Louisville, Kentucky, business.

The Louisville Metro Emergency Services reported on social media a “hazardous materials incident” at 1901 Payne St., in Louisville. The address belongs to a facility operated by Givaudan Sense Colour, a manufacturer of food colorings for soft drinks and other products, according to officials and online records.

Louisville Mayor Craig Greenberg said emergency teams responded to the blast around 3 p.m. News outlets reported that neighbors heard what sounded like an explosion coming from the business. Overhead news video footage showed an industrial building with a large hole in its roof.

“The cause at this point of the explosion is unknown,” Greenberg said in a news conference. No one died in the explosion, he added.

Greenberg said officials spoke to employees inside the plant. “They have initially conveyed that everything was normal activity when the explosion occurred,” he said.

The Louisville Fire Department said in a post on the social platform X that multiple agencies were responding to a “large-scale incident.”

The Louisville Metro Emergency Services first urged people within a mile of the business to shelter in place, but that order was lifted in the afternoon. An evacuation order for the two surrounding blocks around the site of the explosion was still in place Tuesday afternoon.