519 Norris st, Norristown, Pa. 2 Alarms - 042

911 center received numerous calls for the dwelling fire. F/D arrived to heavy fire in the rear of a 2 story m.o.r. Extension to the D-1, D-2 exposures. Heavy fire thru the roof. Evac tones sounded due to volume of fire and power lines down. Exterior attack to knock the bulk of the fire before re-entering the bldgs.