"I started raking it out of the air conditioner vent. I thought it was garbage and I was going to shovel it up, but I bent down to pick it up, and it was a stack of $100 bills, and then more and more kept coming," Trista Wright said Tuesday on CNN.
By an unofficial count, it was more than $30,000.
Wright and fellow students notified the organizers of their church mission, who told the St. Bernard Parish Sheriff's Office.
The woman who owned the house, who has asked that she not be identified, was as shocked as Wright.
"She was speechless," said Wright, a 19-year-old student who was among 175 Georgia college students spending their week off volunteering in the city.
Deputy Gary Adams verified the identity of the woman who owned the home.
Adams said it is not uncommon to find weapons or medications behind the walls of homes, but this was the biggest sum of hidden money he had heard of. "It's good to see someone find something like that and turn it over to proper authorities and the rightful owner," he said.
The homeowner said she suspects the money belonged to her father, who was wary of banks. The home had been in the family for generations, she said.
The one-story house was flooded to the eaves by Katrina and, aside from the hidden money, none of its contents could be saved, church officials said.