What thousands of residents dealt within their homes after Katrina, New Orleans Fire Department Recovery Chief Tim McConnell found in his fire stations.

"Electrical is destroyed, there was plumbing that needed replacing and the windows and doors are rotting away," he said.

Although thousands of homes and hundreds of the city's buildings were deemed a loss and torn down, many, assessed by the city, using a team of architects and other experts days after the storm, were considered repairable.

Today, that prognosis has changed.

The city says there are at least six public buildings that must be demolished and rebuilt: three Orleans Parish prison buildings, fire station engines 3, 8 and 21. City leaders say they are still analyzing some police stations but anticipate the same result.

"We expect there may be more buildings in this process but this is the right way to do this so we are not renovating a building that at the end of day won't have the structural integrity we expect," said Cynthia Sylvain-Lear, Chief Administrative Officer for the City of New Orleans.

"City leaders say part of the problem was once they made it inside of these buildings, especially the multi-story buildings, they realized the damage was far more extensive than they thought.

"We had temporary repairs and we didn't see all of the things that needed to be done, and now we see them," said Dr. Ed Blakely, Recovery Director for the City of New Orleans.

Sylvain-Lear said the city found the issues after another team of experts went back inside the buildings, this time for a comprehensive evaluation.

They deemed the prison buildings and fire stations unrepairable if the structure was corroded by salt water, or if the damages were not reasonable to repair. They also evaluated the cost of repairing the damage, versus the cost to replace the structure.

Sylvain-Lear said the next step is to appeal to FEMA for the funding.

"What we are doing now is working with more professionals for the information in support of the claims that the cost of these buildings to be renovated are significantly higher than cost to demolish and rebuild," she said.