Inexperience and a lack of planning, discipline and leadership undermined the US response to Hurricane Katrina, a White House report has concluded.
President Bush (c) presented the report to his cabinet
Federal disaster response plans had "significant flaws", it says.
Among 125 recommendations in the report is a call for more control to be handed to the Pentagon in similar disasters.
The report is the latest in a string of critical judgements on the response to the hurricane which hit last August, killing about 1,300 people.
Compiled by White House homeland security adviser Frances Townsend, the report highlights 11 key areas in need of improvement in case of future disasters.
Most of the recommendations focus on the need for communication between government departments, federal agencies and relief organisations.
Among the suggestions, the report says:
- A Pentagon contact should be embedded within emergency teams handling potential disasters, but the department should lead the disaster effort only in "extraordinary circumstances"
- The federal government should not be the first authority to respond to a disaster, but should help state and local authorities
- The departments of homeland security and defence should jointly plan the military's support in disasters
- There should be closer ties between the National Guard and homeland security forces.
The federal response to Hurricane Katrina, which pounded New Orleans and the Gulf Coast, was widely criticised at the time and has remained a target in the months afterwards.
Michael Brown, who was head of the Federal Emergency Management Agency (Fema) at the time of the storm, resigned during the initial crisis.
Homeland Security Secretary Michael Chertoff has also come in for criticism from both houses of Congress.
"Hurricane Katrina was a deadly reminder that we can and must do better, and we will," Ms Townsend wrote in a letter to US President George W Bush.
"This is the first and foremost lesson we learned from the death and devastation caused by our country's most destructive natural disaster: no matter how prepared we think we are, we must work every day to improve."
Earlier this month, a Republican-dominated House of Representatives special committee singled out Mr Chertoff and White House staff for criticism.
Mr Chertoff acted "late, ineffectively or not at all", the committee concluded. White House staff failed to give President Bush all relevant information.
A separate report into the response to the hurricane by the Government Accountability Office, a congressional audit body, also found fault with the federal response.
The Senate homeland security committee has also heard a stream of testimony from those involved in the response, but has yet to issue a report.