EMPLOYEE WAS UNLOADING 6 FT TIMBERS FROM A FLATCAR IN THE TRACK ENTRY ON D-5 PANEL. AS HE STARTED TO TURN TO HIS LEFT TO THROW THE TIMBER DOWN HIS RIGHT FOOT SLIPPED ON THE WET BOTTOM AND HE F ELT A SHARP PAIN IN HIS RIGHT KNEE. HE HAS BEEN DIAGNOSED WITH A TORN MENISCUS CARTILAGE IN HIS RT KNEE.