UNITED STATES
DEPARTMENT OF LABOR

Sometime between 8:00 a.m. and 8:23 a.m. on May 28, 1999, Employee #1, a heavy equipment operator, was using an Hitachi track-type excavator to clear and grade an area between two apartment complexes to create additional parking spaces. The soil and gravel bedding that was being removed was located over an existing underground parking garage. Employee #1 was rotating the excavators' arm/bucket from one side to the other to move soil between piles when the roof of the parking garage collapsed. The excavator dropped between 4 and 5 ft toward the parking garage, although its fall was minimized by the cushioning effect of the garage structure and by the soil that poured into the newly created hole. Employee #1 sustained minor injuries and did not require hospitalization. Subsequent investigation revealed the following factors: 1) the parking garage roof was overloaded even though the area below had been shored; 2) there had not been adequate, frequent inspections by a competent person of the areas where the soil spoil piles were placed; 3) Employee #1 had not been adequately instructed regarding how much soil could be staged over the existing parking garage. On the day of the accident, only the track-type excavator was involved in the site clearing operation; on previous days, a second rubber-wheeled backhoe had been used to remove the piles of soil created by the excavator.