Cheswold was alerted at 1442 hours to send an engine to cover Dover's main station while they were fighting a building fire at 1093 South Governor's Avenue. Engine 43-4 responded with 4 firefighters to Dover's station. Shortly after arriving, the engine was ordered to the fire scene and added two Dover firefighters (Hoyt and Hall) to bring the crew to 6. Immediately upon arrival, the crew was put to work on the roof to make a trench cut near the "D" side of the structure. Conditions on the roof began to deteriorate rapidly and the crew was ordered to evacuate. Engine 43-4 was then ordered to supply Dover engine 6. Engineer Dempsey laid 900' of 5" supply line to a hydrant south of the fire scene. The crew was released and sat in heavy race traffic while attempting to get back to Cheswold. Utility 43-9 responded back to the fire scene with a collapse technician as part of the Kent County Special Operations Team to stabilze the building so that the fire investigators could safely operate.