Transcript for Hurricane Harvey evacuees airlifted out of horrific flood zones
Reporter: Day 6 of hurricane Harvey, and there are few signs the chaos is letting up. Here at this makeshift shelter at an elementary school near Beaumont, 110 miles east of Houston, desperation is setting in. You need your medicine? Yeah. I've got to have it. So take it. Take whatever you need. Take the medicine. Reporter: It's another race against time as a nearby dam is reportedly about to overflow. What's the problem? Apparently, a lot of people in this school were still unclear what's going on. All of them were stranded congregating here because this is one of the few dry areas around here. Basically nowhere for them to go but up. I'm with a U.S. Navy search and rescue flight, one of dozens of helicopters buzzing Beaumont. What I didn't know is that I would be acting as an extra set of hands. We're okay. We're okay. Shep. They're inside. They're getting stuff. They're coming in right now. Helping the 14 members of the Mitchell family grab whatever they can. All right, folks, let's go. Reporter: After the frenzy in the school there's the rush to the chopper. Dorothy Mitchell crying as I help her to the helicopter. You can't hear it over the thundering engine, but she's saying "Where do we go now?" They all pile in. Those precious few belongings. And those little dogs. As we lift off, the trauma of displacement sets in. And below, they get their first glimpse of the devastation they've just escaped. Right now they're taking them to another shelter. It is a dry er area, higher ground. Reporter: Beaumont tonight is an island. Surrounded by water but not a drop to drink. The failed water supply forced roughly 200 patients to be evacuated from the Baptist hospital here. And all across the horizon a mangled landscape forever changed. These satellite images showing area rivers before and after. Pretty extensive flooding in here. Reporter: In unincorporated Alvin, Texas between Houston and the gulf -- Chances are that most of these structures here had water inside them. Reporter: In the town of Katy 40 miles west of Houston row after row of houses still submerged. All of this area is underwater. Reporter: Still, nearly a week later, miles and miles of nothing but brown glassy water. But if you look down you see swarms of volunteers cutting through that water, hauling folks out. In vidor my colleague gio Benitez went out to childhood best friends Carlo and Jonah for their third day of rescue. I know the do the same for us. Reporter: Here even the cattle are stranded. The boats spot Mike bedare out the window. He gets on with his wife, Brenda, suitcases and their pet bird. Then it's the short ferry ride to dry land. We thought it would never happen to us. We're probably like millions of other people that it's happened to. Oh, it'll never happen to me. It did. Reporter: In some places people are fleeing but so many like sir jelani and her family are returning home. This is where we would sit and read books with our kids. We would just hang out with them and chill. Reporter: Trying to piece together whatever is left. All my kids' birthdays we've celebrated in this home. I just hope that they can keep those memories instead of the memory they had last when they were here, which is being up on the second floor and just trapped and the water is just rising. Reporter: Eventually, with no other way out, they had to swim for their lives. My 9-year-old, Yusef, he was inconsolable. He just started crying, and he was saying, "Mom, I'm going to drown. We're going to drown in this water, and I can't handle it." It was just something a mother should not have to tell her kids and to go through because you're there to provide safety and shelter and comfort. Reporter: Back down in the mireland area of Houston, one of the hardest-hit sections, rich goulash lined up with the remains of his household possessions. Well, that's life. We've got our sofa, dresser, boxsprings, mattress. That's pretty much everything you accumulate through life. Reporter: He showed my colleague Victor Oquendo the damage inside. That's about your water line. We lost everything that was on the countertops as well. This refrigerator was actually on this wall. Reporter: His loss especially acute. He just moved in this past April. You can see you can't even close some of them. Reporter: And he's a storm reconstruction expert. You were prepared. You know what to do, what to expect when you walk back into a home. We were probably a little more prepared than most for what we were dealing with. But it's still -- when you walk in and see what your life has become, it can be difficult. Reporter: Compounding the troubles in Texas, an explosion at the Arkema chemical plant in Crosby, 30 miles northeast of Houston. The incident reportedly triggered when chemical-filled refrigeration containers failed, warming the oxygen peroxide inside, causing them to burst into smoke and flames. ABC's Clayton Sandell went to Crosby. What does it mean for people's health? What does it mean for people's health? You don't want to stand in smoke, do you? Reporter: And from FEMA an even more alarming message. Yes, the plume is incredibly dangerous. Reporter: EPA administrator Scott Pruitt issued a statement today saying in part "There are no concentrations of concern for toxic materials reported at this time." But more than 20 emergency medical workers and sheriff's deputies exposed to the chemicals were treated and released today. And residents within a mile and a half radius of the plant have been evacuated. The U.S. Chemical safety board is now investigating. Earlier today vice president Mike pence toured the devastation firsthand in rockport, even pitching in on the recovery effort, offering comfort at a Baptist church. You've inspired the nation by your resilience and by your courage. And we just came here to commend you and to encourage you and to assure you that we'll be there. As the president often says, we're one American family. Reporter: The vice president promising Texas will get what it needs. My colleague Jon Karl was on the trip with him. Is he going to put that threat to the side now and concentrate on rebuilding here? President trump's made it clear, very clear that we're going to keep our promise to the American people. We've seen great progress -- Even if that means a shutdown? Illegal immigration on our southern border and enforcing our laws. The president's made it clear we're going to stand firm. The priority right now for president trump and for this administration is these families. Reporter: Almost a week in Harvey's toll is now becoming clear. And the worst isn't over in Beaumont. We dropped the families and Dorothy Mitchell and those dogs at a new shelter. They thanked their Navy heroes and us with those sweet hugs, and we jumped back in the chopper. We landed at St. Elizabeth hospital nearby, switched out with a dialysis patient. It was there we learned this level 3 trauma center is running low on supplies. We only have about 16 dialysis patients that we're slowly transferring out, and I think we have supplies for three or four days, but after that we're going to run out. Reporter: What folks here aren't running low on is heart. We had no car. So we hitched a ride, trying to find those families. So we are at the shelter here, and we can't find our friend Dorothy and her family. The mitchells and Smiths weren't there, but we pushed on. That shelter was being evacuated also. They weren't there, and neither would all of these folks be in just a couple of hours. We learned every shelter in Beaumont would be evacuated with the rivers still rising. For "Nightline" I'm Matt Gutman
This transcript has been automatically generated and may not be 100% accurate.