On April 8, 2008, a 24-year old male volunteer Deputy Fire Chief (the victim, serving as the Incident Commander), was killed when struck by a motorized water monitor and 30 feet of aluminum pipe that was "launched" from an elevated aerial ladder at an industrial fire in Pennsylvania. The ladder was normally transported in the rescue mode with the monitor pinned to the second section of ladder so that the waterway would not be in the way if the ladder was set up for rescue operations. At the incident scene, when the waterway was pressurized, the monitor and its support bracket, along with the last 30-foot section of pipe was launched off the aerial ladder by the force of the water in the pipe. The monitor flew approximately 75 feet and fell, striking the Incident Commander on the head, killing him instantly. Another fire fighter standing next to the victim was knocked down but not seriously injured. After the incident, the waterway anchor pin was found on the ground, in front of the truck's cab. The waterway did not include secondary mechanical stops to prevent the separation of the water monitor in the event the anchoring pin was not properly seated. Key contributing factors identified in this investigation include the original equipment design (lack of secondary mechanical stops to prevent separation in the event the anchoring pin was not properly installed), inadequate staffing, the involvement of multiple individuals in setting up and operating the apparatus, and inexperience in setting up the ladder. NIOSH investigators concluded that, to minimize the risk of similar occurrences, fire departments should: 1. ensure that Standard Operating Procedures (SOPs) and/or Guidelines (SOGs) for setting up multi-position waterways include steps to properly position the waterway and to inspect and verify that the locking mechanism (anchoring pin(s), lever, clamps, etc.) are properly installed and functioning as designed before pressurizing the waterway; 2. provide training and practice for fire fighters on the correct method of securing waterways and verifying they are secured (per manufacturer's recommendations); 3. ensure critical tasks are properly supervised; 4. contact aerial ladder manufacturers to retrofit existing aerial ladder trucks with secondary stops or other engineering controls to prevent waterway launches in the event the waterway is improperly anchored; 5. ensure that adequate numbers of staff are available to effectively respond to emergency incidents. Fire apparatus manufacturers should: 1. provide aerial ladder trucks with secondary stops or other mechanical means of preventing inadvertent waterway separation or launch. Standards setting organizations should establish standards that include engineering safeguards to prevent inadvertent waterway separation. Business owners and property managers should address fire hazards and enforce fire prevention measures. Additionally, municipalities, business owners, and authorities having jurisdiction should ensure fire hydrants are inspected and tested on a regular basis.