ALBANY, N.Y. (AP) - Nearly 500 people have been sickened and one child died in the largest E. coli outbreak in state history and possibly one of the worst nationally, health officials said Thursday. The outbreak of the deadly bacteria at the Washington County Fair, about 35 miles north of Albany, was likely caused by the contamination of the fair's water. Health officials said the water supply may have been tainted when rainwater washed over cow feces from a cattle  barn on the fair grounds and ran into an underground aquifer tapped by the fair's wells. Additionally, officials were worried that the contamination may have spread beyond theGreenwich fair.  (more on "biology" page).