The flawed response to Hurricane Katrina by local, state and federal officials has experts worried that the nation is unprepared for another major disaster. Nearly every emergency-response system broke down in the days immediately following the monster storm — the costliest disaster in American history. Some disaster experts say the government's preoccupation with terrorism — including the deployment of thousands of National Guard and Reserve troops in Iraq — has jeopardized domestic emergency-response capabilities. President Bush proposes putting active-duty troops in charge when states and local communities are overwhelmed by a disaster — whether manmade or natural — but many state officials don't want to give up control. Both Congress and the White House are investigating post-Katrina emergency operations to avoid similar mistakes next time. Meanwhile, disaster officials say Katrina showed the need for individual citizens to be prepared to serve as first-responders for their own families.