The chairwoman of a Senate panel that on Wednesday strongly criticized the federal government's response to Hurricane Katrina (search) will be one of 14 senators who on Friday will visit the region ravaged by the storm.

Sen. Susan Collins (search), R-Maine, is expected to join Senate leaders and other chairmen and ranking members of influential committees that have oversight of the Department of Homeland Security, which houses the Federal Emergency Management Agency and other related goverment bureaus.

Senate Majority Leader Bill Frist of Tennessee and Minority Leader Harry Reid of Nevada will lead the delegation. Also traveling are Republican Sens. John Warner of Virginia, James Inhofe of Oklahoma, Mike Enzi of Wyoming, Richard Shelby of Alabama and Thad Cochran of Mississippi. Democrats Dick Durbin of Illinois, Debbie Stabenow of Michigan, Charles Schumer of New York, Ted Kennedy of Massachusetts, Joe Lieberman of Connecticut and Max Baucus of Montana are also heading to the Gulf Coast.

Louisiana Sens. Mary Landrieu (search), a Democrat, and David Vitter (search), a Republican, will meet their colleagues in their home state that day. It is expected the group will extensively tour New Orleans, and will also go to Mississippi and Alabama.

Frist, a double-boarded general surgeon and heart specialist, has been to the disaster zone twice to lend his medical expertise to wounded evacuees in the makeshift hospital at the New Orleans airport. But other senators have held off going to the region because they said they did not want to interrupt the rescue and recovery efforts.

Now, after appropriating some $62 billion, conducting hearings into what went wrong in the response and negotiating a joint bicameral, bipartisan investigation into the recovery, senators say they want to see for themselves what's needed on the ground and what kind of progress is being made. They also want to ask questions about what went wrong with the response.

Already some of those questions are being asked.

Collins, the chairwoman of the Senate Homeland Security and Governmental Affairs Committee, said Wednesday that changes to improve the government response to catastrophic disasters since Sept. 11, 2001, had failed their first major test in Katrina's wake.

Despite billions of dollars to boost disaster preparedness at all levels of government, the response to Katrina was plagued by confusion, communication failures and widespread lack of coordination, Collins said.

"At this point, we would have expected a sharp, crisp response to this terrible tragedy," she said. "Instead, we witnessed what appeared to be a sluggish initial response."

The hearing is the first in a series set to review failures in the nation's readiness and response systems.

Lieberman, the top Democrat on the committee, said the response to Katrina "has shaken the public's confidence in the ability of government at all levels to protect them in a crisis."

Officials from DHS and FEMA did not attend the hearing; lawmakers said they didn't want to disrupt recovery activities. But several former city and state officials testified about their experiences in facing major disasters in their communities.

Former New Orleans Mayor Marc H. Morial (search) was the first to blame the federal government for the "national tragedy" of Katrina. Morial, president of the National Urban League, was New Orleans' mayor from 1994 to 2004.

"This tragedy requires a concerted, dedicated and wholehearted response from our federal government," Morial said in prepared testimony.

"In responding to this crisis, our government's number one priority must be to help protect and restore the lives of the hundreds of thousands of citizens whose worlds have been disrupted and destroyed," he said. "We must every day and in every way put the people first."

Senators are also looking at an array of bills that aim to ease the worries of individuals impacted by Katrina.

Included are proposals to provide Medicaid health benefits to those made homeless by Katrina, lift work rules for welfare recipients, and implement tax changes to help hurricane victims and charitable donors. More comprehensive bills also will follow.

But also emerging are accusations by Republicans that Democrats are seeking to use the tragedy to pass more ambitious legislation that normally would not have much chance in the GOP-dominated Congress.

"In some instances, (Democrats are) trying to up the ante and use this crisis to accomplish goals that maybe they wouldn't have otherwise been able to accomplish without a natural disaster," said Senate Finance Committee Chairman Charles Grassley, R-Iowa. Grassley is at the center of the storm as he negotiates over taxes, welfare and Medicaid.

For example, a House-passed bill to temporarily ease rules requiring that welfare recipients work 30 hours a week for their benefits and extend the welfare program is still pending before the Senate, despite a big push by Frist to clear it for President Bush's signature. Democrats are pressing for a more generous approach.

Elsewhere, Democrats have benefitted from a decision by House Republicans to shelve debate on a permanent repeal of the estate tax, which most Democrats oppose. Other tax cut efforts have been delayed by several weeks or a month to make room for Katrina legislation.

House Democrats have been defeated on a far-reaching Katrina response plan that would have offered housing vouchers, increased unemployment insurance payments and expanded payments for Medicaid coverage for hurricane victims.

On Wednesday afternoon, Reid and Sen. Hillary Rodham Clinton, D-N.Y., abandoned their effort to set up an independent committee to investigate what went wrong with federal, state and local governments' response to Hurricane Katrina. The lawmakers were unable to muster the two-thirds majority vote needed to overcome procedural hurdles in establishing a panel in the vein of the Sept. 11 commission.

Grassley has formally introduced a bipartisan $7 billion tax break plan that would let hurricane victims tap their retirement accounts, assist businesses and encourage charitable donations. A House plan is still taking shape.

FOX News' Trish Turner and The Associated Press contributed to this report.