WASHINGTON – Hazardous materials crews spent early Thursday morning on the scene of an ammonia leak at the Flying Dog Brewery in Frederick, Md.

The brewery is on the 4600 block of Wedgewood Boulevard.

Frederick County Fire and Rescue evacuated the building after receiving the call at 2:02 a.m. Thursday.

The building was ventilated before firefighters cleared the scene at 5:30 a.m.

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