Fifty-one members of the New Orleans Police Department have been fired for abandoning their posts before or shortly after Hurricane Katrina.
New Orleans was devastated by the impact of Hurricane Katrina
Capt Marlon Defillo said the 45 officers and six civilian employees had not reported back for duty.
Another 228 officers were under investigation for allegedly failing to report for duty, he added.
New Orleans police were widely criticised for failing to control lawlessness in Katrina's wake.
The hurricane - one of the worst to hit the US - devastated parts of Louisiana and Mississippi on 29 August, causing massive flooding in New Orleans and killing about 1,000 people.
City police chief Eddie Compass resigned four weeks later.
In a statement following the announcement of the 51 sackings, acting police Superintendent Warren Riley said: "It is unfortunate that some members did not uphold their oath of office.
"We should not dwell on them because they did not have the best interest of the city or their colleagues at heart."
Capt Defillo said 15 officers had resigned while under investigation.
But he added that officers would not be disciplined if they had good reason for not reporting - including those who were trapped on rooftops awaiting evacuation or out of radio contact.
"Forty-five officers resigned because they wanted to go with their families," he said.
"We didn't have any problems with them because they followed procedures."