Inspection Detail

Inspection: 308685643 - Midlands Contracting, Inc.

Inspection Information - Office: Omaha Area Office

Investigation Summary

At approximately 3:30 p.m. on June 19, 2007 Employee #1 was part of a four-person crew from Midlands Contracting, Inc., that was installing a sewer lift station in Imperial, NE. Employee #1 was at the bottom of a 53 ft wide by 150 ft long excavation that had a maximum depth of 37 ft. He was holding an engineering rod so that a coworker, who was also the superintendent, could obtain elevation measurements to determine the actual depth. It was decided that the base of the excavation needed to be leveled so another coworker began using a Caterpillar 330C excavator to scrape the bottom and remove the excess earth. The excavator was located on an 18 ft 6 in. deep ramp on the north end of the excavation. Employee #1 was still in the excavation when the east wall caved in. The initial collapse covered him up to his knees and he stated that he would extricate himself using a hand shovel. Within 30 seconds, a second collapse occurred that completely engulfed him. Employee #1 died of asphyxia. Subsequent investigation found the upper portions of the excavation on the west and south side were sloped. The east wall was previously excavated and had not been sloped due to the location of the old lift station on its border. The north side contained the ramp that that held the excavator. Causal factors in the accident were the failure to properly apply protective, anti-cave-in systems. This was exacerbated by vibrations caused by the excavator, which was in use while Employee #1 was still working within the excavation. The failure to remove the existing sewer lift station also caused the excavation to be unstable because the slab for the building had been undermined.

Keywords: EXCAVATION, ASPHYXIATED, WORK RULES, CONSTRUCTION, VIBRATIONS, UNSTABLE SURFACE, SLOPING, BURIED, CAVE-IN