A nitric acid chemical spill and explosion took place Thursday at a South Plainfield facility.

The leak occurred at the Ferro Corporation at around 4 a.m. The explosion took place when workers tried to clean the vats outside later in the day, officials say. A hazmat team was on the scene Thursday afternoon and took several hours to clean up after the incident.

"I see guys outside moving some boxes. All the sudden, it just blew up," says Robert Guzman, of South Plainfield. "Some orange and some white smoke started coming out [of the building]."