Two Florida cities, Miami and Fort Lauderdale, appeared in the top ten of highest foreclosure rates in the U.S., according to RealtyTrac’s rankings of the nation’s 100 biggest metro areas. Orlando ranked third. Detroit ranked the highest, with 4.92 percent of households in some stage of foreclosure. Authorities say the markets with the most foreclosures had experienced rapid growth and unsustainable price appreciation, or were hit with a widespread economic downturn. Nationwide, foreclosure filings went up 75 percent last year.