On May 27, 2000, a 17-year-old female lifeguard (the victim) died after she fell into a nearly empty swimming pool. On the day of the incident, a crew of four, including the victim, two other lifeguards, and the pool engineer were preparing the pool for the new season. One lifeguard and the pool engineer were working in the filter room while the victim and another lifeguard (coworker) were in the pool, cleaning the floor and sides of the L-shaped pool. The coworker was cleaning the pool at a location where he could not see the victim, when he heard a "thump." He looked up and observed the diving board, which had been placed on its rack the previous day but not secured, falling into the pool. He ran around the corner of the L-shaped pool and saw the victim lying face down in several inches of water in the deepest part of the pool (11 feet, 6 inches deep). The coworker turned the victim face up to prevent her from drowning, moved her out of the water toward the west end of the pool where the pool was less steeply sloped, and called out for help. He stayed with the victim until help arrived. The lifeguard and the pool engineer heard the coworker's call for help and immediately called 911, then went to help the victim. Police and fire department personnel responded within 2 minutes. They determined that the victim had a pulse and respirations and severe head injuries and immediately called for an ambulance. The victim was taken by ambulance to an area hospital and then flown to a regional trauma center where she was pronounced dead 3 days after the incident. NIOSH investigators concluded that, to help prevent similar occurrences, employers should: 1) complete a hazard assessment that identifies hazards present during seasonal pool maintenance, and then develop, implement, and enforce standard operating procedures (SOPs) that, when followed, eliminate hazards or minimize worker exposure to risk of injury; 2) train all workers to recognize the hazards identified in the hazard assessment and train them to follow standard operating procedures (SOPs) designed to minimize their risks.