THE EMPLOYEE WAS IN THE PROCESS OF INSTALLING UTILITIES FROM A SCISSORS DECK. HE PICKED UP A 4 INCH DIAMETER PIPE AND SLIPPED ON THE WET SURFACEOF THE DECK, FELL DOWN ON THE DECK, ROTATING HI S KNEE INWARD. HE WAS TRANSPORTED TO E.R. AND DIAGNOSED AS AN ACUTE LIGAMENTOUS TEAR IN THE LEFT KNEE.