Abstract: Employee #1, the foreman for a trenching contractor, was supervising the backfilling of trenches on a public street using a Caterpillar 950 loader fitted with a back-up alarm that actuates electrically as soon as the machine is put into reverse. On this particular loader, the back-up alarm had been disconnected when some mechanical work was done. The loader had been returned to the site only one day before. Employee #1 was standing behind the wheels of the loader, looking down, and did not see or hear the loader in time. The rear wheel of the loader passed over him, crushing him. Employee #1 survived, but suffered severe internal injuries and multiple fractures to his right arm.