Fire fighters and rescuers search for workers trapped in the collapsed scaffold at a building site of Baotou city, north China's Inner Mongolian Autonomous Region, Aug. 18, 2004. Thirteen workers were injured with three of them in serious condition in the accident, which occurred at the busy downtown quarter of Baotou at about 10:30 a.m. when more than 40 workers were on the 30-meter-tall scaffold.