NEW ORLEANS , Louisiana ( CNN ) -- A federal judge has thrown out a class action lawsuit against the U.S. Army Corps of Engineers over the failure of levees in New Orleans during Hurricane Katrina . Levees failed in several areas , flooding about 80 percent of New Orleans with water up to 20 feet deep . U.S. District Judge Stanwood Duval acknowledged Wednesday that the agency failed to properly safeguard the city , but he ruled that the Corps was protected by the Flood Control Act of 1928 . It shields the federal government from liability when flood control projects fail . The Corps designed the levee system that was supposed to protect the low-lying city . But after Katrina stuck the Gulf Coast on August 29 , 2005 , steel-and-concrete levees eroded and failed in several areas , flooding about 80 percent of the city with water up to 20 feet deep . In 2007 , the Insurance Information Institute estimated insured losses for Katrina across Louisiana at $ 25.3 billion . In his ruling , Stanwood said the Corps deserves blame for its role in the flooding even if it ca n't be held legally responsible . `` While the United States government is immune ... it is not free , nor should it be , from posterity 's judgment concerning its failure to accomplish what was its task , '' Stanwood said , lamenting his inability to take further action . `` It is hopefully within the citizens of the United States ' power to address the failures of our laws and agencies , '' he said . `` If not , it is certain that another tragedy such as this will occur again . '' Stanwood called the story of the Corps failure to protect New Orleans `` heart-wrenching . '' `` Millions of dollars were squandered in building a levee system ... which was known to be inadequate by the Corps ' own calculations , '' the ruling said . The Corps ' own studies recommended upgrades that were never implemented . Plaintiffs attorney Joseph Bruno said he intends to appeal the decision to the U.S. Court of Appeals for the Fifth Circuit . Bruno and other attorneys will hold a news conference Thursday in response to the ruling . Reached in Washington , Corps spokesman Gene Pawlik applauded the decision . `` We agree with the judge 's ruling and ca n't say too terribly much more because there 's other legal matters to be settled , '' he said . A number of other lawsuits remain unsettled in the aftermath of Katrina . Pawlik said the Corps is doing everything it can to improve the city 's much-maligned levee system . `` We 're trying to learn from the lessons of Katrina and put the best system in place for the people of New Orleans , '' he said . E-mail to a friend . CNN 's Eric Marrapodi and Ed Payne contributed to this report .
NEW : Judge Stanwood Duval says Corps deserves blame for role in the flooding . Comment: 1928 law shields the federal government from liability over flood controls . Plaintiffs attorney plans appeal , Thursday news conference .