As Tracy Smith reports, they saved thousands of lives in their own backyard. Smith spoke with several of the rescuers.
"We flew in right after the storm, and the wind was still blowing 50, 60 mph," says rescue pilot Bill Dunbar.
Colleague Jeff Damotta says, "The houses were broken into matchsticks, and the ones that were still standing were up to their rooftops in water."
Added another team member, "It's amazing to see how things can go straight to hell, really fast."
Though it's been more than two weeks since the rescuers got their first glimpse of Katrina's wrath, the images still play daily in their minds, Smith says.
"People were using anything and any means possible to try to signal us," flight mechanic Jason Roberts says.
"Seeing all the people was the thing that had the biggest impact," rescue pilot Maria Roerick says. "The first day, they were just everywhere."
The decisions on who to take and who to leave behind were sometimes difficult.
"You know," Roerick says, "you do the best you can, and that's all based on your background and your values and your training."
"People are sitting there fighting, trying to get in," says flight mechanic Jason Bauer. "They are so scared. You see the look on their faces."
When people rushed the helicopters, they had to be stern.
"You got to just say no," Bauer says. "You got to stick to your priorities. You have to take the kids. You need to take the sick and the people who really need your help, and just let them know that you'll be back for them and not to give up hope."