EE HAD STARTED HIS SHIFT AT 500 AM AND HAD WALKED INTO THE DIESEL SHOP TO SEE IF THE D-9R DOZER THAT HE OPERATES HAD BEEN REPAIRED. THE DOZER HAD BEEN DOWN DUE TO ENGINE PROBLEMS. HE STEPPED U P ON ONE OF THE TRACK ASSEMBLIES, TO LOOK AT THEENGINE, WHEN HE LOST HIS BALANCE AND FELL. WHEN HE FELL HIS RIGHT RIB CAGE STRUCK THE DOZER BLADES PUSH-ARM.