PHILADELPHIA - DECEMBER 7:  A closed Taco Bell restaurant is seen at the Franklin Mills Mall December 7, 2006 in Philadelphia, Pennsylvania. Taco Bell restaurants in the Philadelphia area have closed voluntarily for testing, after five people who contracted an E. coli illness, dined at a Taco Bell restaurant before falling ill. Getty Images logo Getty Images 38 months ago

PHILADELPHIA - DECEMBER 7: A closed Taco Bell restaurant is seen at the Franklin Mills Mall December 7, 2006 in Philadelphia, Pennsylvania. Taco Bell restaurants in the Philadelphia area have closed voluntarily for testing, after five people who contracted an E. coli illness, dined at a Taco Bell restaurant before falling ill.