Abstract: At approximately 1:00 a.m. on October 19, 1992, Employee #1 was guiding a trench shield into place during a trenching operation. The trench shield was being lifted by a Caterpillar 235 excavator. The shield was attached by a 4 leg bridle sling with the bridle sling ring on a hook welded to the excavator bucket. As the shield was being maneuvered into position, the tension on the sling was relaxed and then reapplied. But while the tension was slacked, the ring became partially detached. When the load was reintroduced, the bridle sling unit sprang loose from the hook. The ring struck Employee #1 in the face. Employee #1 required hospitalization.