Abstract: At 10:25 a.m. on May 12, 1999, Employee #1, working for Conco Cement Company, fell from a column. Employee #1 was working with his foreman, Coworker #3, at the time of the accident. Coworker #3 was handing up the embeds to Employee #1. While Employee #1 was up on the column, one of the guys holding up the column was removed from the ground, causing the column to become unstable and fall over. Employee #1 could not escape from under the column because he was wearing fall protection equipment connected to the column. Before Employee #1 went up the column, there were four guys securing the column. While Employee #1 was up on the column, there were two employees from Huber, Hunt and Nichols Company, Coworker #2 and Coworker #4, and one from Ryan engineering, Coworker #5, on the ground near one of the guy stakes, excavating the area. At some point, Coworker #2 and Coworker #4 noticed the stake was removed from the ground and they wanted it moved away from their work area. It is unclear whether Coworker #2, Coworker #4 or Coworker #5 initially removed the stake from the ground, but Coworker #2 did state that he moved the cable. Shortly thereafter, Coworker #3 noticed the stake not in the ground and came over and moved the cable and stake to the concrete slab near the column where Employee #1 was working. The column that fell over was unique to this job. It was called a hinged column and there were only four them out of the several hundred columns at the jobsite. The column was engineered so that the outer rebar is not completely embedded in the concrete. The guys were then needed to make the column stable at all times so that it would not fall over. Once the guy was removed from the ground, the column became unstable and collapsed at the point where the outer rebar would normally go into the concrete slab. Employee #1 stated that he did not know that this column was different from all the others at the site, nor were there any safety meetings discussing this column before he began his work. Once Employee #3 noticed that the guy was not secure to the ground, he should have immediately repositioned the guy into the ground. Instead, he just moved it and allowed Employee #1 to continue working. Employee #1 was up on a steel column approximately 20 feet tall installing embeds when the column fell over on him. Employee #1 seriously injured his right leg and was taken to San Francisco General Hospital for treatment and was hospitalized.