In a sign of the magnitude of the disaster, more than 30,000 people are expected to be housed in shelters even as rescue officials were still piecing together the extent of the damage to homes and businesses, said William “Brock” Long, admistrator of the Federal Emergency Management Agency.

The already-dire circumstances were complicated by the release of water from two reservoirs opened to relieve the stress caused by a downpour that was threatening to equal or exceed in just a few days the area’s average rainfall for a full year…

Across the nation’s fourth-largest city and suburbs many miles away, families scrambled to get out of their fast-flooding homes. Rescuers — in many cases neighbors helping neighbors — in fishing boats, huge dump trucks and even front-end loaders battled driving rains to move people to shelter. Some used inflatable toys to ferry their families out of inundated neighborhoods, wading through chest-deep water on foot while the ­region was under near-constant tornado watches.