Homeland Security Secretary Michael Chertoff testifies before a House Select Committee hearing on the preparation and response to Hurricane Katrina

Secretary of Homeland Security Michael Chertoff faced tough questioning Wednesday from members of Congress about the much criticized government response to Hurricane Katrina.  Mr. Chertoff was the highest-ranking U.S. official to appear before a congressional panel investigating what went wrong with disaster response.

Mr. Chertoff's appearance was highly anticipated, as lawmakers probe the federal, state and local responses to Hurricane Katrina, and with a new storm, Hurricane Wilma, bearing down on the state of Florida.

Among issues examined by congressional committees in recent weeks have been the effectiveness of FEMA (the federal emergency agency) Mr. Chertoff's own actions and those of the former emergency management chief, and the responsibilities of local and state leaders.

Outlining a range of actions taken or planned to improve responses in the future, Secretary Chertoff said some hard lessons have been learned from Hurricane Katrina.

"The tragedy emphasized how critical it is that we ensure our planning and response capabilities, perform in an integrated fashion with seamless integrity and efficiency in any type of disaster situation," said Mr. Chertoff.

As lawmakers recalled chaotic scenes in New Orleans following Hurricane Katrina, Mr. Chertoff said he is committed to ensuring quicker evacuations from disaster zones, and getting food and other supplies into these areas.

One widely broadcast scene from New Orleans, that of school buses that were to have been used for evacuation, but were swamped by the hurricane's waters and were unable to move, produced this exchange between Republican Congressman Harold Rogers and Mr. Chertoff:

ROGERS:  "Did the buses ever move?"

CHERTOFF:  "I have certainly seen pictures of a lot of buses underwater that suggest that they did not move."

ROGERS:  "And they were lined up in a parking lot, end on end?"

CHERTOFF: "Yeah, I have seen those pictures."

ROGERS:  "And they were never used to evacuate people out of hospitals or schools or nursing homes or the like.  Where were the drivers of those buses if you know."

CHERTOFF:  "I don't know."

Which authority was in charge of those buses was not discussed.

Mr. Chertoff rejected suggestions by some that he was not sufficiently engaged in hurricane response efforts. 

He acknowledged frustration with the performance of Michael Brown, the former head of the Federal Emergency Management Agency (FEMA), noting that he was unable to contact Mr. Brown by phone until late Tuesday after Hurricane Katrina struck.

Secretary Chertoff took issue with Mr. Brown's testimony to Congress that officials in Louisiana were "dysfunctional," and emphasized the need to better integrate efforts with state and local officials, and improve sharing of information.

In a separate congressional hearing, lawmakers sought the views of three state governors about disaster response, amid suggestions the federal government should assume more of a central role from state and local governments.

That brought this response from Florida Governor Jeb Bush, brother of President Bush, and Arizona Governor Janet Napolitano.

BUSH:  "If this responsibility is federalized then that will be as big of a disaster as any natural disaster that hits our communities."

NAPOLITANO:  "We can't do our jobs if it is federalized." 

Governor Bush says his state as well as its local officials are prepared for Hurricane Wilma, which is moving through the Caribbean to an expected Florida landfall, but he urged residents to comply with mandatory evacuation orders.