WASHINGTON (AP) - Housing construction rose in September despite new uncertainties about consumers' willingness to make big-ticket purchases in the wake of the terror attacks and mounting layoffs. The Commerce Department reported Wednesday that builders broke ground on 1.57 million housing units at a seasonally adjusted annual rate last month, a 1.7 percent increase. That followed a sharp 6.7 percent drop in August. Many analysts were expecting housing starts to fall by around 2 percent in September on the belief that builders would hold off on new projects, given new economic uncertainties created by the Sept. 11 attacks. In their aftermath, layoffs have rocketed, retail sales have plunged and consumer and business confidence in the economy have been badly shaken.