was directly above the second-level walkway. Collapse Approximately 1,600 people gathered in the atrium for a tea dance on the evening of July 17, 1981. The second-level walkway held about 40 people at approximately 7:05 p.m., with more on the third and an additional 16 to 20 on the fourth. The fourth-floor bridge was suspended directly over the second-floor bridge, with the third-floor walkway offset several yards from the others. Guests heard popping noises and a loud crack moments before the fourth-floor walkway dropped several inches, paused, then fell completely onto the second-floor walkway. Both walkways then fell to the crowded lobby floor. A diner at the 42nd-floor revolving restaurant atop the Hyatt said it felt like an explosion. The rescue operation lasted 14 hours, directed by Kansas City emergency medical director Joseph Waeckerle. Survivors were buried beneath the walkways' many tons of steel, concrete and glass, which the fire department's jacks could not move. Volunteers responded to an appeal and brought jacks, flashlights, compressors, jackhammers, concrete saws and generators from construction companies and suppliers. They also brought cranes and forced the booms through the lobby windows to lift debris. Deputy Fire Chief Arnett Williams recalled this immediate outpouring from the industrial community: "They said 'take what you want'. I don't know if all those people got their equipment back. But no one has ever asked for an accounting and no one has ever submitted a bill." The dead were taken to a ground-floor exhibition area as a makeshift morgue, and the hotel's driveway and lawn were used as a triage area. Able survivors were instructed to leave the hotel to simplify the rescue effort, and morphine was given to the mortally injured. Rescuers often had to dismember bodies to reach survivors among the wreckage. A surgeon spent 20 minutes amputating one victim's pinned and unsalvageable leg with a chainsaw; that victim later died. Blood centers quickly received lineups of hundreds of donors. The Life Line helicopter pilot compared the carnage to the Vietnam War but in greater numbers here. Water flooded the lobby from the hotel's ruptured sprinkler system and put trapped survivors at risk of drowning. The final rescued victim, Mark Williams, spent more than nine hours pinned underneath the lower skywalk with both legs dislocated and having nearly drowned before the water was shut off. Visibility was poor because of dust and because the power had been