NEW YORK (AP) — With a ladder truck, a rescue demonstration and a chance for children to spray a fire hose, a Harlem block party this month honored the 150-year history of the nation's largest fire department. Minority firefighter leaders say the department needs to do more, and demographic shifts haven't always changed a firehouse culture that grew over generations of near-uniformity, as largely Irish-American and Italian-American men followed their fathers, uncles and grandfathers into the job. A current of antipathy spilled into the forefront recently, when Deputy Chief Paul Mannix was docked 50 days' pay amid an investigation into leaks of damaging information about minority firefighters' performance. With 10,800 uniformed members, the FDNY is more than twice the size of any other U.S.