Katrina, with winds of 155 mph, is upgraded to catergory four. New Orleans warned it might be in path.
* SUNDAY, 28 August
New Orleans Mayor, Ray Nagin, orders mandatory evacuation of the city after Katrina becomes maximum-strength category five. Motorways jammed. Those unable or unwilling to leave, spend night in shelters. George Bush declares state of emergency.
* MONDAY, 29 August
Katrina drops to category four before it makes landfall at Mobile, Alabama, becoming a tropical storm as it moves inland. Search and rescue teams wait for worst of storm to pass before entering disaster zone. Winds of more than 100mph tear off part of roof of Superdome where 9,000 people take shelter. Power lines cut. Two levees breach and lake water pours into New Orleans.
* TUESDAY, 30 August
Government of New Orleans regroups in Baton Rouge. Mayor Nagin estimates 80 per cent of New Orleans is under water. He criticises the lack of co-ordination in relief efforts. Water continues to rise. City hospitals flood. Pentagon says it will send five ships, but four are several days away. More than 12,000 seek shelter in Superdome. Hundreds of people feared dead along the Mississippi coast.
* WEDNESDAY, 31 August
Mayor Nagin orders total evacuation of city. Bush convenes federal task force. Public health emergency declared along Gulf coast to speed up delivery of food, water and fuel. Armed police ordered to cease rescue operations and tackle lawlessness. Military transport planes carry only seriously ill and injured to Houston.
* THURSDAY, 1 September
New Orleans descends into anarchy, with reports of looting, shootings and rapes. Conditions at Superdome and Convention Centre continue to deteriorate. More than 45,000 refugees now taking shelter. Bush criticised for slow response. Engineers struggle with levees.
* FRIDAY, 2 September
Bush flies to Mobile, Alabama. Congress approves $10.5bn (£5.8bn) in aid. Full federal response comes only after dialogue between local and federal officials erupted in anger.
* SATURDAY, 3 September
Government calls on military to take over New Orleans. Largest airlift on US soil rescues thousands. People stranded for days are evacuated. Fireboats train hoses on a waterfront chemical plant which blew up on Friday. Three cruise liners chartered for accommodation. Relief workers open a mortuary and begin collecting corpses, many floating in streets. Pump stations still not activated.
* SUNDAY, 4 September
Refugees taken to sports stadiums and other large shelters in Texas and northern Louisiana. Troops begin moving emergency supplies in New Orleans.