Abstract: On May 16, 2008, Employee #1 was operating a skid-steer riding mower (Toro Z-Master, 27 horsepower, Z557, Model Number 74246, Serial Number 240002732) to cut grass on an 18-degree slope behind a house near a lake. The mower's roll-over protection system was lowered and his seatbelt was not fastened. Three other employees were performing yard work in the front of the house. Employee #1 was found under the mower, which was upside down in the lake. He had drowned. There were no witnesses to the accident. The incident was caused by mower use on a slope greater than the manufacturer's limitation of 15 degrees, failure to heed safety warning labels on the mower, and lack of training on safe operating practices.