Abstract: At approximately 3:00 p.m. on June 10, 2002, Employee #1 and a coworker of Nordby Wine Caves Inc. were applying an initial layer of shotcrete, as permanent ground support to the right rib of a tunnel. The location was at the south heading, and the last 11 feet of the final distance reach, of the main passage of a wine cave type tunnel that was being constructed. Employee #1 was handling the hose nozzle and directly applying the shotcrete and the coworker was assisting by maneuvering the shotcrete hose during the operation. The shotcrete operation began following inspection of the walls and roof to determine of additional ground support, other than shotcrete, was needed. The inspection did not reveal cracks, fissures, loose ground, or other necessity to install additional ground support. The shotcrete was to be applied to 11 feet of the tunnel ribs, arches and crown. Shotcrete was applied on the left rib first, starting at the toe and working higher along the rib with each pass through the arches to the crown, than back to the rib again to increase the thickness along the rib. Then the same pattern was applied to the right rib and arches to the crown. The overall result is 3 to 4 inches thick on the ribs and 1 to 2 inches thick in the arches and at the crown. The crown had been completed for about one minute and Employee #1 was working the secondary passes on the right rib when a slab of shotcrete coated rock materials fell from overhead. One end of the slab first released distal from Employee #1's position, and then the end proximal to the coworker. The slab fell either at an angle or in an arching motion, and first struck Employee #1 substantially on the left side of the head and face, knocking him to the invert, and then falling on top of him and breaking apart. There was no warning of any kind. The shotcrete pump was making noise, the impact noise of the shotcrete could by heard, and the coworker could hear his own breathing and grunting from the heavy work of maneuvering the hose. The shotrecte was being applied at the standard 90 degree angle to the surface, so both men were looking at the work and saw no indication of the falling slab. Emergency action was immediately implemented by the coworker and Employee #1 was ready for medical transport before the arrival of fire department paramedics. The combined weight of the rock materials and shotcrete coating was estimated at 2,131 pounds. Employee #1 received a closed head injury (trauma induced), a left eye injury, a fractured left mandible, facial abrasions, fractured clavicle, fractured rib, and a right pneumothorax (collapsed lung). The injuries resulted in prolonged hospitalization and prolonged recovery.