On February 21, 2006, a 62-year-old male volunteer fire captain (Victim # 1) and a 23-year old male volunteer fire fighter (Victim # 2) died when they were struck by a collapsing exterior wall of a one-story commercial building during overhaul operations following a structure fire. The building was approximately 50 years old and had been renovated several times with at least two additions. The exterior walls were constructed of concrete blocks. However, multiple layers of different siding materials covering the front wall of the building hid the underlying concrete block wall from view. The fire was reported at approximately 1728 hours and fire fighters from a number of fire departments were on-scene for several hours containing the fire to the building. The heavy timber roof collapsed after burning for over 2 hours. The last mutual aid crew was released before 2100 hours. The remaining fire fighters noticed that concrete block walls on both sides of the structure were starting to lean outward so sections of the walls that were bulging outward were pulled down. At approximately 2130 hours, the two victims, along with a third fire fighter, were stretching a 1 ¾ inch handline to the front entrance to put water on hotspots when the front wall collapsed, striking the two victims. The third fire fighter was handling the hoseline a few feet behind the two victims and was struck on the foot by falling debris, narrowly missing serious injury. NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should: 1. establish and monitor a collapse zone for structures that have become unstable due to fire damage; 2. conduct pre-incident planning and inspections of buildings within their jurisdictions to facilitate development of safe fire ground strategies and tactics; 3. develop, implement, and enforce written standard operating guidelines (SOGs) or standard operating procedures (SOPs) for all aspects of fire fighting operations; 4. train all fire fighting personnel in the risks and hazards related to structural collapse; 5. ensure that fire fighters wear a full array of turnout clothing and personal protective equipment (i.e. SCBA and PASS device) appropriate for the assigned tasks while participating in fire suppression and overhaul activities. Also, manufacturers, equipment designers, and researchers should continue to pursue emerging technologies for evaluating and monitoring the stability of buildings exposed to fireground conditions.