The welding activity routinely triggered alarms from the building's smoke detectors, so much so that staff at the China Arts & Crafts store that occupied the bottom three floors had wrapped plastic around the fire alarms to muffle the sound. Furthermore, workers were found to have cut metal with a welder, contrary to building codes. Thus, when a stray piece of hot metal fell from the thirteenth floor, sparking a fire in the second floor lift lobby, no one paid much attention, believing that it was part of the normal welding activity. A welder discovered the fire, and alerted the fire department. A second emergency call was made one minute later, when a dental assistant on the 13th floor discovered dense smoke in the hallway.