Roberts calls it "a rescue operation the likes of which no one here has seen in 40 years."
And Police Capt. Donald Curole should know: He saw the last one after Hurricane Betsy in 1965.
"I had members of my family, if they hadn't been rescued they'd have been dead," he says. "So, I'm just trying to pay back the favor of people years ago."
The flooding began in one area of New Orleans at 8 a.m. when Katrina's storm surge breeched the levee.
Sheila Martin and her daughter rode out the storm in an attic crawlspace, then pushed out a roof vent to escape.
Sanford Green and his wife survived 12 hours of nightmarish winds, and water that rose to the ceiling.
"There is a God," he says. "That's all I can tell you. God is good, 'cause we could have drowned in there."
Volunteers from the police and fire departments brought their own boats to what Roberts describes as "this bizarre Venice on the Mississippi," navigating neighborhoods — and front yards.
There were local heroes, too, Roberts says.
Jarvis Perry put his family in a small skiff, then swam all the way to higher ground at the bottom of an interstate on-ramp.
Still, says Perry, "So many people have lost a whole lot of things. … It's very disturbing, and it's a horrible scene."
There was never enough room on the rescue boats, Roberts say. Every one of them came back loaded to the gunwales.
Some survivors needed urgent medical care. Others just needed to finally touch dry ground.
And, as the sun went down, the boats went out again.