Crews prepare to seal California dam spillway that forced evacuations

By Sharon Bernstein OROVILLE, Calif. (Reuters) - Operators of the nation's tallest dam prepared on Monday to shore up a crumbling emergency spillway with bags of rock while bleeding off excess water from a rain-swollen lake to ease the threat of inundating the Northern California communities under evacuation orders downstream. Some 188,000 residents in the river valley below the Lake Oroville Dam, 65 miles (105 km) north of Sacramento, were ordered from their homes on Sunday when one of two dama