Abstract: At approximately 8:05 a.m. on July 8, 2000, Employee #1, of C.W. Poss, Inc., was at a construction site in Diamond Bar, CA. He was driving a 1-ton Ford 454 flatbed truck, license #3R83007, with a coworker passenger, tools, a welding machine, a crane, and an air compressor mounted on its bed, for a gross weight of 13,500 lb. They were headed up a 20 degree hill on a steep dirt road when another coworker, driving a fully-loaded 4,400 gal water truck, license #SE410598, began coming down the same road. The coworker said he looked down the hill and did not see any vehicles coming up when he set off; Employee #1 later stated that he looked up the hill and did not see any vehicles headed down. Employee #1 was coming around a curve when he saw the coworker's 36,000 lb truck stopped on a plateau just above the steep portion of the hill. Employee #1 had his truck in granny gear and kept going up the hill, expecting the coworker to back up. But, the coworker was waiting for Employee #1 to back his truck down the hill. Employee #1 said he attempted to pass the water truck, but the dirt road was not wide enough and he was forced to drive onto a soft, banked shoulder. The rear wheels of the vehicle dug into the soft dirt and he could not get traction. The engine died and the truck began sliding backward down the hill. Employee #1 turned the steering wheel so that the back of the truck bed would hit the side of the hill and stop it, but when the truck bed hit the vehicle rolled over on its left side. The coworker climbed out of the passenger side window and yelled for Employee #1 to follow, but he could not get out. The truck then resumed sliding down the road and eventually rolled over the side of the hill for about 180 ft. Employee #1 sustained head trauma, a laceration under his left arm, a fractured right knee, and a fractured right elbow. He was transported to the UC-Irvine Medical Center, where he was hospitalized for three days. The coworker driving the water truck later stated that when he saw Employee #1 was going to pass, he pulled his truck a little to the right, but was afraid of getting too close to the edge and going over the side of the hill. He added that the side mirrors of the two trucks touched as the flatbed truck passed by. The supervisor did not witness the accident. The employer was cited for an accident-related violation of T8CCR 1509 (a).