At a news briefing in Texas, US President George W. Bush said that the emergency response to Hurricane Gustav was "a lot better" than the reaction to the 2005 Hurricane Katrina, which left more than 1 800 people killed and New Orleans devastated.
"The coordination on this storm is a lot better than during Katrina," President Bush said at the state Emergency Operations Center in Austin.
The President cancelled his trip to the Republican National Convention in Minnesota starting on Monday and travelled to Austin and San Antonio in Texas instead, about 640km away from the Gustav-hit area in Louisiana.
Gustav was downgraded to a Category two storm by mid-Monday morning, compared to Katrina, a Category three storm.
CNN TV footage broadcast live from New Orleans showed that strong wind swirled rains and swept the city, leaving floodwater overtopping an industrial canal levee.
Eqecat Inc, a California-based risk modeler, said Monday in a statement that Gustav would result in up to $12 billion in insured losses, and a long-term 5 percent cut to oil and natural gas production in the region, mostly in Louisiana.
The loss included wind and water damage to commercial and residential structures, and business operating suspension due to shutdowns and a surge in costs of supplies.