Inspection Detail

Inspection: 307457580 - J H Thompson & Sons Inc

Inspection Information - Office: San Bernardino District Office

Investigation Summary

At 1:30 p.m. on July 1, 2005, Employee #1 was working as a backhoe operator for J. H. Thompson & Sons, Inc., in Yucca Valley, CA. He had been operating a Caterpillar Model Number 446 backhoe, with Serial Number 503, digging an excavation. After digging approximately 200 feet of the excavation, he got off the backhoe and entered the excavation. Employee #1 and several coworkers were inside the excavation, which was 5 feet 3 inches deep, 3 feet wide at the bottom, and 13 feet wide at the top. They were installing 12-inch-diameter C-900 PVC water main pipe, using a 6-foot-long, 3-inch-diameter steel push bar to move the pipes into position. Employee #1 was using the push bar, when the excavation caved in. Though his coworkers were uninjured, Employee #1 was buried up to his waist. He sustained a fractured collar bone. He was hospitalized for 6 days at Hi-Desert Medical Center, in Joshua Tree, CA. An individual who was designated as a competent person stated that the soil was classified as class B, that it was benched back 1:1, and that he had been told that the width of the excavation at the top was 13 feet. The general contractor provided a geotechnical engineering report that indicated that the trench should have been classified as class C soil and benched back 1.5:1. The employer is a grading and excavating contractor.

Keywords: EXCAVATION, FRACTURE, COLLARBONE, TRENCH, WATER PIPE, CAVE-IN, BACKHOE