1983年5月31日,山东省某地区建筑工程公司第二施工队人民医院门诊楼工地,临时开卷扬机的青工小A未经领导同意早退回家,并擅自将机器交给壮工小B操作。时临下班之际,小B用餐心切,心神不定,又不熟悉操作要领,当一老抹灰工在10米多高处的料盘上放空 On May 31, 1983, at the construction site of the People’s Hospital of the Second Construction Team of a construction engineering company in an area of ​​Shandong Province, Qinggongxiao A, who temporarily opened the winch, returned home without the consent of the leader and arbitrarily handed over the machine to the Zhuanggong Small B. operating. When the time comes to work, the small B is eager to eat, is uncertain, and is not familiar with the operation essentials, when an old plasterer is emptying on a tray more than 10 meters high.