Ed Koch, the tough, fast-talking mayor of New York in the turbulent 1980s, died Friday, aged 88.
Koch had been facing heart and other health problems.
The current mayor, Michael Bloomberg, praised Koch as a "tireless, fearless and guileless civic leader" for his role in rescuing New York from the brink of financial collapse.
"Ed helped lift the city out of its darkest days and set it on course for an incredible comeback," Bloomberg said. He ordered flags to be lowered to half-mast.
Koch's greatest success was in tough financial management during his three terms between 1978 and 1989. But he also presided over an era when AIDS, homelessness and crime were rampant across the biggest US city.
More than anything Koch is remembered for his rough and colorful New Yorker style. "How'm I doin'?" was his trademark greeting to voters.