Approx 1130 hours on May 30th, units from the 1st and 2nd Battalions were notified of a possible house fire in the Potomac Station section of Engine 22’s first due. With multiple calls reported and multiple sightings of “Large Columns” in the sky. A few volunteers made their way to the station to get additional units on the street. Truck Co. 606 added on to assignment as the truck company on the RIT Level I assignment. Units went on scene with a 2 story SFD with fire showing all floors. T606 positioned on Side C of the structure and reported to Side A to pair up with the initial RIT crews. After a brief stint in the RIT task force, members were reassigned to relieve companies operating hoselines on the exterior. During that time period a significant collapse of the structure occurred and crews were forced to regroup and devise a new plan. Units operated on-scene for approx 3 hours. Engine Co. 303 (Dulles Airport) was sent to backfill station 6 during this incident.