Authorities said no one was injured when the beams -- each weighing several tons -- came hurtling down from one of the new towers being built at the site of the September 11 , 2001 , terrorist attacks . Three steel beams fall after a crane cable snaps . The collapse of the bridge was caused by an electrical fault in one of its support cables that snapped and sent two concrete columns plummeting to their deaths.
Three steel beams fall after a crane cable snaps . The collapse of the bridge was caused by an electrical fault in one of its support cables that snapped and sent two concrete columns plummeting to their deaths.