EE WAS BACKING A BULK POWDER TRUCK BETWEEN 1ST &2ND ROW OF DRILL HOLES TO BE LOADED FROM THE OUTSIDE EDGE OF THE DRILL BENCH PAD. HE WAS BETWEENTHE ROWS. PROCEEDING BACKWARDS HE WAS UNAWARE OF THE 1ST ROW ANGLED INWARDS TOWARD THE 2ND. THE RIGHT TANDEN WHEEL DROPPED OFF THE EDGE. AS THE TRUCK OVERTURNED HE LEAPT FROM IT LANDING ON THESPOIL BANK & SLID UNDERNEATH ROLLING TRUCK.