A construction worker was seriously injured when a sheet pile fell from the grips of the sheet driving hammer as it was being maneuvered into position. The site and equipment were documented and a series of graphics was prepared to explain the circumstances of the accident. The sheet driving hammer and controls were tested and found to function normally. It was concluded that the sheet was inadvertently released as it was swung into position. The use of safety cables to secure the steel sheet to the hammer would have prevented this tragic accident.