The spring ice bridge, formed with lake ice that broke up and flowed over Niagara Falls, is blocking the gorge and delaying the tourist boat season. The Maid of the Mist fleet remains drydocked on the Canadian side of the gorge. But good news arrived today. Removal of the Niagara River ice boom, which began on April 22, was completed Thursday. "Everything's out now," said U.S. Army Corps of Engineers spokesman John Derbyshire. "We didn't go into May, at least." Thursday crews removed the last 11 anchored spans and two trailing sections to complete the job in a daylong effort.