TIERRA VERDE - In the shadow of its towering replacement and several hovering news helicopters, much of what's left of the old Pinellas Bayway Bridge plummeted into the Intracoastal Waterway this afternoon. The eastbound span of the new bridge was closed to traffic as crews prepared to take down the structure with an underwater detonation. The explosion was scheduled for noon, but there were delays, including one caused by a wildlife sighting. A group of onlookers gathered at a small beachfront behind a condominium complex southeast of the bridge. As they waited for the action, workers drove pilings for the yet-to-be-built westbound span, a sound that echoed throughout the area. The bridge's westbound portion is expected to be completed in the summer of 2014.