The Mississippi River crested at nearly 48 feet on Tuesday, causing hardship in some of the South’s poorest areas. With water rushing at a rate of 900 million gallons a minute, some 1,300 homes were threatened, and nearly 500 people living near Memphis were forced into shelters. Crops were washed away by backed-up tributaries. Nineteen casinos along the swollen river will be shut down by the end of the week, costing local governments approximately $13 million in monthly taxes and leaving 13,000 employees temporarily out of work. President Barack Obama has declared 15 Tennessee counties federal disaster areas due to flooding and severe weather.