Eleven people were transported to local hospitals after an explosion Tuesday afternoon at a local natural food coloring factory in Louisville, Kentucky, local authorities said.

A stay-at-home order was issued within a one-mile radius of the “hazardous materials incident” at Givaudan Sense Color in the Clifton neighborhood Tuesday afternoon.

The cause of the explosion is not known and remains under investigation, Louisville Mayor Craig Greenberg said at a news conference Tuesday afternoon.

The incident happened at 1901 Payne St., officials said.

Kentucky Governor Andy Beshear encouraged citizens to follow the advice of local officials.

“Britain and I pray for the safety of everyone involved,” Beshear said in a statement.

This is a developing story. Check back for updates.