On Thursday August 12, 2010 at 1320 hours units were dispatched to 1875 Connecticut Ave NW In Washington, DC for smoke coming from the building. Engine 9 and Engine 21 arrived simultaneously to report light smoke emanating from the grates on the sidewalk. It was determined that it was a underground electrical transformer was on fire adjacent to the building and a Foam Unit and Haz-Mat Task Force were called to assist along with a Working Fire Dispatch and evacuations were ordered of the 10 story 300x100 high-rise in fear of potential spread of fire. The Washington Hilton across the street also restricted access to their 10-story hotel. Initial fire attack was performed with Purple-K agent from Twin Agent Unit #1. Mutual Aide was requested from Metropolitan Washington Airport Authority for Foam Unit 337. Units remained on the scene with Pepco for about 4 hours to determine if the transformer contained PCB's. In addition all members were rehabbed utilizing the Rehab and Canteen Units. Connecticut Ave and Florida Ave were closed in the immediate area during most of the rush hour.