Hurricane Frances, which may become the costliest storm to hit the U.S. in a dozen years, headed toward Florida, forcing about 2.5 million people to flee their homes.

Frances, which is wider than Hurricane Charley, may cost the most in damage since 1992's Hurricane Andrew. Andrew, a Category 5 hurricane, cost insurers $15.5 billion in claims, or $20.3 billion in today's dollars.

The hurricane is expected to slam the state's east coast between 2 a.m. and 8 a.m. local time tomorrow, less than a month after Hurricane Charley caused billions of dollars in damage along Florida's west coast.