A RUN-OFF ELECTION WAS UNDERWAY SATURDAY IN NEW ORLEANS TO DECIDE WHO WILL LEAD THE FLOOD-RAVAGED CITY THROUGH THE COMING YEARS OF REBUILDING AND RECOVERING, ACCORDING TO DPA. NINE MONTHS AFTER HURRICANE KATRINA ROCKED THE US GULF COAST AND LEFT NEW ORLEANS UNDER WATER, EMBATTLED MAYOR RAY NAGIN WAS LOCKED IN A CONTEST AGAINST LOUISIANA STATE LIEUTENANT GOVERNOR MITCH LANDRIEU, AFTER NEITHER OF THE TOP TWO FINISHERS WAS ABLE TO GAIN A MAJORITY IN APRIL'S FIRST ROUND OF VOTING. NAGIN, 49, AN AFRICAN-AMERICAN WHO BLAMED THE FEDERAL GOVERNMENT FOR THE CITY'S SHOCKINGLY WEAK RESPONSE TO KATRINA BUT WHOSE MANAGEMENT OF THE CRISIS HAS ALSO BEEN WIDELY CONDEMNED, WON 38 PER CENT IN THE EARLIER ELECTION. THE CHALLENGER'S SISTER IS A US SENATOR, AND THEIR FATHER, MOON LANDRIEU, WAS THE LAST WHITE NEW ORLEANS MAYOR AND WAS WIDELY BELOVED IN THE BLACK COMMUNITY DESPITE HIS RACE. BOTH CANDIDATES IN THE OFFICIALLY NON-PARTISAN ELECTION ARE MEMBERS OF THE CENTRE-LEFT DEMOCRATIC PARTY.