Some sort of ammonia spill at South San Francisco's Columbus Salame, the same meat processing plant that played host to a four-alarm fire in July, caused an early morning evacuation. Also, reports confirm that "as many as 12 ambulances are in the area of the UPS customer center at 657 Forbes Blvd., assisting those who have been exposed to the chemical through a decontamination process before releasing them."

16 people, the Chron reports, were treated and released. "The leak appears to be accidental and has since been capped, authorities said. The cause of the leak is under investigation."

Check out video of Hazmat crews in action after the jump.