NEW ORLEANS — Mountains of debris, collapsing houses, a weather-ravaged stadium: It's yours for $35 a person — $28 for kids.

Gray Line New Orleans began a bus tour Wednesday of the devastation wreaked by Hurricane Katrina, and demand was high enough that the company added a third tour on the first day.

Some New Orleans residents have questioned whether such tours are morbid exploitation, or a good way to help people grasp the enormity of the disaster. Even some of those on the first tour Wednesday morning had mixed emotions.

"I felt guilty about going out and looking, but it's something we had to do," said Toni Stone of Harrisonburg, Va., who took the tour with her husband.

The three-hour tour, called "Hurricane Katrina — America's Worst Catastrophe," takes passengers down Canal Street, where many businesses remain boarded up after the floods that hit 80 percent of the city.

Wednesday morning's tour was given by Joe Gendusa, a retired teacher and lifelong New Orleans resident. He told them about his own grim experiences, including being trapped by floodwaters in a tall building downtown where he had sought shelter, and seeing dead bodies.

"This is not just a tour for me," said Gendusa, whose childhood home in the Gentilly neighborhood was flooded. "This is my home."

The tour swung by the Superdome, where thousands of people took refuge and awaited rescue for days. A bright white temporary coating, contrasting with the dirtier off-white color of the original roof, covers the holes Katrina ripped open Aug. 29.

From there it was off to a vacant Morial Convention Center — another place of refuge where some died waiting for rescue — and then to some of the worst-hit residential neighborhoods, Lakeview and Gentilly, where roof-high water pushed homes off foundations, mountains of debris remain and collapsing houses await demolition.

The tour did not go through the Ninth Ward, another of the worst-hit areas. Authorities have warned that damage along some of the debris-laden streets is so severe that travel could be hazardous.

A Wednesday morning tour was added to the day's itinerary after two afternoon bus tours, each holding 24 passengers, sold out. Other, smaller organized tours have also been arranged in the area in recent weeks.

Local Gray Line executive Julee Pearce said she expects more sellout tours. Gray Line phones have been busy with callers interested in the excursions, including inquiries from school groups, she said.

The company has said $3 from every Katrina tour ticket will be donated to Katrina-related charities. Passengers also get a packet with pictures of the destruction and a form letter asking them to write their congressional representatives to urge them to help the city.

"We want you to take pictures to go home and show your friends that New Orleans took a hit," Gendusa said. "We need your help."

In addition, Pearce said the excursions will help revive the area's tourism industry. Gray Line New Orleans had 65 employees before the storm but now has only six.

Not everyone is convinced that the tours will help the city's recovery.

Callers to a radio talk show early Wednesday had varying reactions, some saying the tour was exploitative, others saying it will help people realize the extent of the damage.

At a restaurant near the tour route, flood victim Eric Tapp seemed resigned. He shook his head when asked if he resented the bus tour running through his ravaged Gentilly neighborhood.

"It's an open city," he said. "There's nothing you can do about it."