Rescue workers were ordered from the scene shortly after 5 p.m.yesterday, as now-familiar rolling clouds of smoke confirmed thedemise of yet another downtown building. City officials last nightconfirmed the collapse of Five World Trade Center, a nine-storyoffice building. A second cave-in at the Center's south toweroccurred at roughly 5:30 p.m., leveling what was left of thatstructure.

City Fire Commissioner Thomas Von Essen confirmed last night ata press conference that engineers are inspecting 1 Liberty Plaza, a54-story office tower at Broadway and Liberty Street, after reportsof a crack in the building. Building owner Brookfield Propertieshas issued a statement denying structural damage to thebuilding.

The nearby Hilton Millennium Hilton Hotel, located at 55 ChurchSt. is said to be in imminent danger of collapse, though the extentof the damage to that structure is unknown. Marriott officialsyesterday confirmed severe structural damage to its hotel at ThreeWorld Trade Center, another building said to be in danger offalling.