9:59:00: The South Tower of the World Trade Center collapses, 56 minutes after the impact of Flight 175. Its destruction is viewed and heard by a vast television and radio audience. As the roar of the collapse goes silent, tremendous gray-white clouds of pulverized concrete and gypsum rush through the streets. Most observers think a new explosion or impact has produced smoke and debris that now obscures the South Tower, but once the wind clears the smoke, it becomes clear that the building is no longer standing. NY1 correspondent Kristen Shaughnessy, on the scene of the disaster, reports on the collapse of the South Tower at the instant it begins, while ABC News correspondent Don Dahler, who was home at the time of the incident and lived near the site, reports to anchor Peter Jennings on air that he has witnessed the tower collapse; Dahler's report is perhaps the first broadcast specific confirmation of a collapse as his report is filed seconds after the event.