Abstract: A THREE-STORY STEEL BUILDING WAS BEING CONSTRUCTED USING SOLID WEB STEEL COLUMNS, JOIST GIRDERS, AND OPEN-WEB STEEL JOISTS. THE COLUMNS WERE ERECTED AND TIED TOGETHER WITH JOIST GIRDERS AND TIE JOISTS. ONE BOLT WAS INSTALLED AT EACH CONNECTION. THE OPEN-WEB STEEL JOISTS WERE LAID ON THE STRUCTURE. MOST WERE SHAKEN OUT, BUT SOME WERE IN BUNDLES. BUNDLES OF ROOF DECKING AND FLOOR DECKING WERE PLACED ON TOP OF THE JOISTS AND JOIST GIRDERS. THE BUILDING WAS BEING PLUMBED. NONE OF THE JOISTS WERE PERMANENTLY INSTALLED. AT ABOUT 5:15 PM ON MAY 12, 1987, THE ENTIRE STRUCTURE COLLAPSED. ALTHOUGH SEVERAL EMPLOYEES WERE UNDER THE STRUCTURE WHEN IT COLLAPSED, THEY WERE ABLE TO GET OUT IN TIME TO AVOID INJURY.