1) You take them to designated hurricane shelters that have been pre-approved by the local government.

Approximately 9,000 residents and 550 National Guardsmen rode out the night in the Superdome as Katrina came ashore. Maj. Gen. Bennett C. Landreneau, Adjutant General for the Louisiana National Guard, said that the number of people taking shelter in the Superdome rose to around 15,000 to 20,000 as search and rescue teams brought more people to the Superdome from areas hit hard by the flooding.

The Superdome was built to withstand most catastrophes; the roof was ostensibly estimated to be able to withstand winds with speeds of up to 200 mph; flood waters could still possibly reach the second level 20 feet from the ground, making the structure an unreliable shelter in severe rain and wind. When looking into the origins of this 200 mph wind security in the Superdome, CNN reported that no engineering study had ever been completed on the amount of wind the structure can withstand; the building's engineering study was underway as Hurricane Katrina approached and was put on hold. It was used as an emergency shelter although it was neither designed nor tested for the task. However, the damage to the roof was not catastrophic, with just 2 relatively small holes and the ripping off of most of the easily replaceable white rubber membrane on the outer layer.

On August 29, 2005, at about 9:00 AM EDT, reports from inside the Superdome were that part of the roof was "peeling off," daylight could be seen from inside the dome, and rain was pouring in. The Associated Press stated there were two holes, "each about 15 to 20 feet long and 4 to 5 feet wide", and that water was making its way in at elevator shafts and other small openings.

When the flooding began on August 30, the Superdome began to slowly fill with water, though it remained confined to the field level. Later that day, Governor Blanco ordered New Orleans completely evacuated.

http://en.wikipedia.org/wiki/Louisiana_Superdome

The storm, which was the costliest hurricane as well as one of the deadliest natural disasters in U.S. history, made its second and third landfalls in the Gulf Coast region on August 29, 2005 as a powerful Category 3 hurricane. By August 31, 2005, eighty percent (80%) of the city was flooded, with some parts under 20 feet (6.1 meters) of water. Four of the city's protective levees were breached, including the 17th Street Canal levee, the Industrial Canal levee, and the London Avenue Canal floodwall.

Although more than 80% of residents evacuated, the rest remained. The Louisiana Superdome, used as a designated "refuge of last resort" for those who remained in the city, also sustained significant damage, including two sections of the roof that were compromised, and the dome's waterproof membrane had essentially been peeled off. As the city flooded, many who remained in their homes had to swim for their lives, wade through deep water, or remain trapped in their attics or on their rooftops.

Although Mayor Ray Nagin ordered a mandatory evacuation of the city, many remained voluntarily, which a CNN writer described as "gambling with their own lives." Reasons were numerous, including feeling their homes or the buildings they planned to stay in offered sufficent protection, lack of financial resources or access to transportation, a feeling of obligation to protect their property, or fearing that the tribulations of evacuation (which many went throught the previous year with Ivan) were more of a hazard than the hurricane risk.

A "refuge of last resort," was designated at the Louisiana Superdome. Beginning at noon on August 28 and running for several hours, city buses were redeployed to shuttle local residents from 12 pickup points throughout the city to the, "shelters of last resort." Several hundred school buses were also available, yet they were not deployed, apparently because not enough drivers could be found.

http://en.wikipedia.org/wiki/Effect_of_Hurricane_Katrina_on_New_Orleans

President Bush authorized the dispatch of 7,200 active-duty ground troops to the area -- the first major commitment of regular ground forces in the crisis -- and the Pentagon announced that an additional 10,000 National Guard troops will be sent to Louisiana and Mississippi, raising the total Guard contingent to about 40,000.

http://www.washingtonpost.com/wp-dyn/content/article/2005/09/03/AR2005090301680.html

So...tell me..what was Bush suppose to do? Airlift a guestimated 30,000 people in a day? How do you expect the military to get into a FLOODED city?

National Guard Official Admits Iraq Deployment Affected Katrina Response
Scores of members of the Mississippi National Guard stationed in Iraq have been denied 15-day leaves in order to help their displaced families. The commanders told them that there were too few U.S. troops in Iraq to spare them. 40 percent of Mississippi's National Guard force and 35 percent of Louisiana's is in Iraq. Meanwhile, for the first time, a high-ranking National Guard official has admitted that the Guard's response to the hurricane was hindered by the high number of troops in Iraq. Lt. Gen. Steven Blum, chief of the National Guard Bureau, told CNN that "arguably" a day or so of response time was lost due to the absence of the Guard troops in Iraq. He said, "Had that brigade been at home and not in Iraq, their expertise and capabilities could have been brought to bear."

http://www.democracynow.org/article.pl?sid=05/09/12/1426204

What if Al Qaeda blew up the levees,
Would New Orleans have been safer that way,
Sheltered by our government’s protection,
Or was someone just not home that day?

'Let’s Impeach the President' - Neil Young