At 21:56, April 17, Station 5,2,1 and 9 were dispatched to a reported chimney fire.  The home owner reported smoke in the structure with a crackling noise coming from the roof.  The Duty Officer arrived on location to find a two story single family residence with smoke showing from the roof area.  Alarm was upgraded to a working fire assignment.  Interior crew advanced on attack line into the structure to the second floor.  22:03 Fire showing through the roof.  22:04 (7 minutes 56 seconds from dispatch) exterior chimney lost structural stability and fell through the roof into the center of the structure.  Evacuation tone signaled and interior crews exited the structure.  Second alarm assignment requested.  A defensive fire attack was initiated.  Master streams from Truck 1 and Truck 2 knocked the fire down.  Interior crews extinguished balance of the fire.  The fire was declared under control at 23:58.  The homeowner received aid and displacement services from the American Red Cross.  The cause of the fire is under investigation.