Good evening. We are here in tampa bay, florida, where the republican national convention is awaiting a high stakes speech from paul ryan tonight. But first, we want to take you, right away, to the... See More
Good evening. We are here in tampa bay, florida, where the republican national convention is awaiting a high stakes speech from paul ryan tonight. But first, we want to take you, right away, to the gulf coast, at this moment, isaac unleashing a deluge of water, a torrent of water on louisiana. And this is the seventh anniversary of hurricane katrina. Once again, we are seeing in some neighborhoods, families being rescued from their homes, from their roofs. Take a look at the pictures still coming in. Houses under water. Boats and helicopters trying to help families flee to safety. Dogs in hand. And at this hour, isaac is now considered a tropical storm, but it's a super soaker, and virtually stalled over louisiana. More than 20 inches of rain, after winds that did gust up to 100 miles per hour. Officials, though, say the levees are holding. Our extreme weather team spent the day in the storm zone and abc's weather editor sam champion, once again, starts us off in new orleans tonight. Sam? Reporter: Good evening, diane. And we are once again along the mississippi river in new orleans. If you think about it, isaac is only officially a visitor in louisiana for 24 hours. But it's been torrential rain and in general, about 7 to 14 inches of rain coming in at times. But there are some extreme exceptions. Take a look at the map here. We're going to show you an area in the ninth ward, that is about 22 inches of rain in that area, probably about 22 1/2 inches of rain. And then, there's 17 inches of rain in ottman park. It is likely we'll see incredible rainfall totals from the system as it continues to move up. 1:00 p.M. Thursday, going to be in northern louisiana. 1:00 p.M. Friday, in northern arkansas. 1:00 p.M. Saturday, in central missouri. And if you look at the map here, it's about 1:00 p.M. On saturday in central illinois. Brushes by the great lakes and then finds itself in central ohio by the time we get to monday. That's a long time for a tropical storm to be making its way through america's heartland. In each place, it will dump rain, diane. A lot of rain and possible flooding. Thank you, sam. Now, we move to abc's bill weir, in one of those hardest hit communities sam mentioned on the louisiana coast. Bill covered katrina, as did sam, and he is back there tonight. Reporter: On the seventh anniversary of katrina, it was another day of rooftop rescues. Because while the new $14 billion federal levee system around new orleans held tight, isaac proved too much for the old earthen levees out in the rural suburbs south of town. And dozens of families who ignored evacuation orders woke up with the realization that their homes were drowning, fast. We had to break through the ceiling and go through the attic. And they took us out of the attic into the boat. It's very bad down there. Very bad. I've lived there for 53 years and this is my fist time seeing something like this. This ain't never, ever happen d to us. This is a shame. Reporter: Some were rescued by game wardens. Others relying on the kindness of strangers, like jesse. After watching a dozen feet of water swallow their home, they jumped in their fishing boat and went hunting for the helpless. Each say he saved 60 people and dozens of pets. They were caught in the attic, it's hard to know if they were in there or not, if they couldn't have hacked their way out. We never seen anything like this. Not even katrina. Reporter: Billy nungesser who came to fame during the bp spill was back in front of cameras, imploring his neighbors to get out before another breech. We've got about six hours. That's enough time to get everybody out. We need you to move quickly. Reporter: But responders has to spend hours waiting for winds to calm before they could evacuate this nursing home. While other authorities fanned out in an urgent effort to get families to flee, like this family. My mom actually named me after hurricane anita, which PASSED ON AUGUST 29th, THE DAY I Was born. Reporter: She was born under a water sign. I guess, you could say. As for the people who may need the coast guard is sending two helicopters with hoists and rescue divers. A lot of people here saying no one thought there would be more roof rescues seven years after katrina, given this was just a category 1 storm. But all this water, throwing a wrench into another day in new orleans. It is haunting to see again. Thank you so much, bill. And now, we want to move on down the coast. Our experienced storm chaser, abc's meteorologist ginger zee, in long beach, mississippi, where tonight, they are not just battling floods and high winds, but reports of or the nay do tornadoes touching down. Ginger? Reporter: Diane, I am standing on what was highway 90, the storm surge has been pushing up and over, flooding this highway. The median is right in front of me, but there's no chance of seeing it. And this needle-like rain and pounding winds have been with us all day. Also inland, major flooding going on -- hundreds of roads are closed just in the state of mississippi. People under water, their homes, some schools reporting flooding. And finally as if that wasn't enough, a third threat. We've had tornado warnings, a swarm of them around us all day. Diane? All right, ginger, thanks to you. And ginger, you should know, and bill and sam and the full abc news team will be out in the storm throughout the night. You can follow along with their updates, they will be frequent, on our website, abcnews.Com.
This transcript has been automatically generated and may not be 100% accurate.