Abstract: On March 11, 2010, Employee #1 was setting a portable building on the property of a Palestine Independent School District high school, as part of a three-person work crew. The crew used two blue jacks at each end of the building, and four smaller hydraulic jacks at the center of the building (two in front, and two in back) to lift and lower the building to the appropriate elevation. The crew was working underneath the building, between the floor beams, stacking cribbing (piers) to the appropriate height. While waiting for a co-worker to get new cribbing blocks, Employee #1 began sitting upright. Then, without warning, the building shifted and collapsed, killing Employee #1. From the incident investigation, it was determined that the soil was saturated with water due to four consecutive days of rain; that the 12-ton bottle jacks being used to support the elevated building were not used on a hard surface; that the employer did not follow the manufacturer's instructions on the safe use of jacks; and did not train employees on the safe use of jacks.