UPDATE 6:22 The scene has been cleared, ABC7 reports.
Prince George's firefighters, paramedics and a hazmat team responded to the scene around 12:15 a.m. for reports of a chemical leak, fire officials say. Upon arrival, hazmat crews determined ammonia was leaking from a 100-gallon tank, which prompted an evacuation of about 100 employees at the warehouse.
Officials say there was about 100 gallons of the product left in the tank and atmospheric monitoring and testing equipment indicated that the building's interior had high levels of the product.
The Smithfield Packing, a food processing plant in Landover, has been evacuated early Tuesday morning due to an ammonia leak, Prince George's Fire reports.
Emergency crews responded to the scene on Columbia Park Road around 12:30 a.m.
There is no word on what caused the leak or if anyone became sick.