Almost two years after Hurricane Katrina devastated the U.S. Gulf Coast, the National Guard says it remains ill-prepared to respond to a sudden disaster. Some lawmakers are calling for better planning in the event of a large-scale natural disaster or terrorist attack. Leta Hong Fincher has more.

Army Lieutenant General Steven Blum, head of the U.S. National Guard, says that if there were advance notice, his division today would be able to respond to a domestic emergency such as Hurricane Katrina.  "We are far better prepared today than we were just several months ago, and dramatically better prepared than we were five years ago."

But Blum says the National Guard is still unprepared for a sudden, major disaster: not just a hurricane, but a terrorist nuclear attack.

"In a predictable event,? explained the general, ?we can make do with not having enough equipment, because we can move it around. In a no-notice event, we're at risk, and we're at significant risk."

At a Senate hearing on U.S. disaster response, Senate independent Joseph Lieberman cited a recent study that said Washington has failed to plan for a catastrophe such as a terrorist nuclear attack. The study was carried out by Ashton Carter and William Perry of the Preventive Defense Project of Harvard and Stanford Universities. It found that the U.S. government still has no comprehensive response plan for the day after a nuclear attack.

"Policymakers whom they [defense scholars] questioned in Washington, they found, continue to believe that state and local officials will be able to control the situation the day after a nuclear attack,? said Mr. Lieberman. ?Yet [Ashton] Carter and [William] Perry argue that as the fiasco after Hurricane Katrina suggests, most cities and states will quickly be overwhelmed by the magnitude of the humanitarian, law-and-order and logistical challenges of responding to a nuclear detonation."

Lieberman and Republican Senator Susan Collins have called on the U.S. Government Accountability Office to investigate current national disaster-response plans, to make sure they are complete and well-understood.