NEW ORLEANS - The Army Corps of Engineers raced to patch New Orleans' fractured levee system Tuesday and residents were forced to decide yet again whether to stay or go as a new, rapidly strengthening hurricane threatened to flood the city anew.

The new threat was Hurricane Rita, which strengthened into a 105-mph Category 2 storm as it barreled past the Florida Keys into the Gulf of Mexico.

Forecasters said the storm could strengthen to a 131-mph-plus Category 4 and hit Texas by the end of the week. But a slight turn to the right was possible, and engineers warned that even a glancing blow to New Orleans and as little as 6 inches of rain could swamp the city's levees.