On February 16, 2004, three male ironworkers (aged 30, 42, and 44 years old) were killed, and three male ironworkers and two male operating engineers were seriously injured while working on a bridge construction project. On February 18, 2004, one of the seriously injured ironworkers died in a local trauma center. The incident occurred during the launching and subsequent catastrophic collapse of a launching gantry (LG) (a horizontal framework of steel trusses that span the distance between two elevated bridge piers, designed to lift pre-cast segments of roadway). The LG involved in this incident was positioned on an interstate bridge construction project. All four victims were performing various required tasks for launching (re-positioning) the LG when the collapse occurred. EMS and rescue units were dispatched and arrived within minutes of the collapse, at which time three of the fatally injured workers were pronounced dead on scene. NIOSH investigators concluded that, in order to prevent similar occurrences, Employers should: 1. ensure that the manufacturer's operating procedures are followed or provide alternative protective measures such as engineering controls in order to ensure safe operations; 2. ensure that workers comprehend and understand safety training and safety instructions, and that issues such as language barriers do not interfere with the effectiveness of the training, particularly when employees are required to work with unfamiliar equipment; and, 3. develop and implement written standard operating procedures (SOPs) for unfamiliar equipment, and provide training on the SOPs to all employees involved in equipment operation. In addition, employers and general contractors should ensure that various components of a construction process are compatible. State and Federal Occupational Safety and Health Administrations should consider developing requirements for inspecting and certifying cantilever launching gantries similar to those currently required for mobile cranes.