GONAIVES, Haiti—Floodwaters frustrated efforts by Argentine peacekeepers to distribute food at orphanages marooned by Tropical Storm Hanna on Thursday. They hunkered down in their base as desperate people begged for food and water outside the gates.

A Haitian politician struggling to gauge the extent of the damage in Haiti’s fourth-largest city helicoptered into the U.N. compound and said the situation is critical.

“If they don’t have food, it can be dangerous,” Sen. Youri Latortue said Thursday after arriving from Haiti’s capital. “They can’t wait.”

Half the homes in the low-lying city of 160,000 remain flooded in Hanna’s wake, estimated Lt. Sergio Hoj, spokesman for the Argentine battalion.

Some 250,000 people are affected in the Gonaives region, including 70,000 in 150 shelters across the city, according to an international official who spoke on condition of anonymity because he was not authorized to release the information.

The official death toll rose to 61 Thursday as Hanna finally moved north with near-hurricane winds on a path toward the southeastern U.S. coast. But there was no way of knowing how many people might be dead in the chaos, or how many had been driven from their homes.

And forecasters warned that Hurricane Ike could hit the Western hemisphere’s poorest country next week.

Gonaives lies in a flat river plain between the ocean and deforested mountains that run with mud even in light rains. Hanna swirled over Haiti for four days, dumping vast amounts of water, blowing down fruit trees and ruining stores of food as it swamped tin-roofed houses.

Many of the thousands of people who fled to rooftops, balconies and higher ground have gone without food for days, and safe drinking water was in short supply as the fetid carcasses of drowned farm animals bobbed in soupy floodwaters.

Businesses were closed—both because of flooding and for fear of looting.

People in water up to their knees shouted to peacekeepers to give them drinking water, and women on balconies waved empty pots and spoons.

The Argentine soldiers have plucked residents from rooftops that were the only visible parts of their houses, but had little capacity to deliver food and water.