EMPLOYEE STATES THAT HE LOST CONTROL OF THE EMPTY CAT 773 DUMP TRUCK HE WAS DRIVING. THE TRUCK VEERED, RAN THROUGH THE PROTECTIVE BERM AND OFF A 70'-HIGH WALL. (EMPLOYEE: NEW HIRE IN TRAINING. TRUCK LANDED ON ITS TOP. RESULTED IN PASSENGER FATALITY - BLUNT FORCE TRAUMA INSIDE CAB OF TRUCK; NEITHER WAS THROWN FROM CAB.)