Sandifer, who celebrated her 40th birthday on Aug. 29, the day the storm hit, said her husband and teenagers refused to accompany her because they did not want to hear such sad stories or see all the misery.
But she came because "this is history. This is something I really need to know."
As is the practice on every tour, Dupuy explained that $3 of the $35 ticket goes to one of several Katrina-related charities. He passed out a list so passengers could choose from projects benefiting programs for children, healthcare, animals, housing -- or, if they chose, specify another charity.
Dupuy also asked passengers to sign a petition to be sent to President Bush and other federal officials, urging that New Orleans be rebuilt. Everyone signed.
"We have to rebuild," said Trevor Colestock, 30, a teacher who came from Hollywood, Fla. "We rebuilt Western Europe after World War II, and we can't rebuild New Orleans, one of the great cities in America? What kind of a country is this?"
Getting off the bus, Susan Breaux of Baton Rouge said she was sorry her 17-year-old son had stayed behind.
The teen had said he thought it would be too depressing, seeing his mother's hometown in such bad shape.
"But this is what is here, right now," Breaux said. "It is important to see this. You can't forget it. You can't forget what you have seen today if you grew up here and you knew how beautiful and alive this city was."
Others seemed to share that view. Back at the starting point, a line of people waited for cancellations for the next devastation tour, one hour away.