TAMPA, Fla. (WFLA) – A possible explosion was reported Tuesday afternoon at a BJ’s Wholesale Club in Sanford.

According to WESH 2 News, firefighters heard reports of the explosion, but hadn’t seen any signs of one just yet.

Firefighters said the store’s dry chemical system went off, according to WESH. They don’t know what caused the system to go off.

The building itself and cars in the area were covered in chemicals.

At least one person was treated at the scene, WESH reported.