PERFORMING ROUTINE ELECTRICAL HELPER INSTALLATION TASKS. EE WAS IN THE PROCESS OF CARRYING CONDUIT FROM A STORAGE PILE TO THE WORK SITE. WHILE CARRYING CONDUIT ON SHOULDER, STEPPED INTO A BLIND HOLE APPROX 12"" DEEP. EE FELT SORENESS IN HIP AREA. NEXT DAY, EE WAS IN PAIN WHEN REPORTING FOR WORK, SENT TO HOSPITAL. XRAY REVEALED A FRACTURE OF THIRD VERTEBRA.