ST. PETERSBURG — Firefighters were cleaning up a chemical mess Friday night after vats full of acid erupted in flames at a St. Petersburg warehouse.

The fire began at about 6 p.m. inside the M & P Plating Inc. building at 3645 Eighth Ave. S., fire officials said. One or two vats full of acid somehow ignited after the business closed.

Someone in the area called 911 after seeing dark smoke pouring from the eaves of the building, officials said. Firefighters soon arrived and extinguished the blaze within an hour, but remained at the scene late into the evening to clean up the various acids and caustic chemicals that were released.

The vats of acid were being used in the plating process, fire officials said. It was not immediately known how the blaze started. The cause was under investigation.