The hurricane left many parts of the city underwater
A lawsuit filed by New Orleans residents against government engineers for damages caused by Hurricane Katrina is to be heard in court in Louisiana.
The residents claim that the US Army Corp of Engineers is liable to pay damages, because of poor maintenance of a shipping channel near the city.
If successful, some 120,000 other residents and firms could seek payouts.
More than 1,800 people died and much of the city was flooded by the devastating 2005 hurricane.
The plaintiffs argue that because of the Corp of Engineers' poor upkeep of the Mississippi River-Gulf Outlet (MRGO), a shipping channel that links the Gulf of Mexico and New Orleans, flooding in the city's St Bernard Parish and Lower Ninth Ward was exacerbated.
"They are responsible," said Lower Ninth Ward resident Lucille Franz, 75, who lost her home in the flood, and whose sister died at a local nursing home.
"We wouldn't have had that kind of water if it hadn't been for the MRGO."
The residents' lawyer described the disaster as "the largest preventable catastrophe in American history".
They are asking for damages of between $300,000 (£206,000) and $400,000 for each individual.
Government lawyers acting on behalf of the Corp of Engineers have not commented on the case, but court documents suggest they will argue that the flooding was caused by Katrina's storm surge, and not by a failure of the MRGO's flood defences.