Transcript for Deadly Hurricane Dorian batters Bahamas as storm impacts US
Reporter: This is what nearly 48 hours of catastrophe looks like. As Dorian, the most powerful storm ever to hit the Bahamas, crawled its way through the islands at times coming to a complete standstill with wind speeds of 180 miles per hour. That's the front porch. The water is about six feet. Reporter: In its wake, utter devastation. At least seven people killed. We can expect more deaths to be recorded. As the monster storm now churns north, it's expected to bring flash flooding and storm surge, leaving millions along the east coast on high alert. This is a very serious storm and a western shift that could bring enormous damage to our state. Reporter: And now, new aerials from the Bahamas' abaco islands show a paradise in ruins. My team and I had been on the island for four days as Dorian seemed to sit right on top of us. At one point, having to take shelter inside a closet as the storm grew ever more violent. We're in what looks like a utility closet that we moved to. This is producer Chris Donato. Reporter: Today, as it finally weakened, we were able to leave our building, which you can see here in this aerial image, it is one of the few in abaco left standing. The more are began when it made landfall as a category five hurricane. You can't even see the house across the street anymore. Reporter: You can see what it's doing here and off in the distance, those waves crashing against the pier. Wind gusts exceeded 220 miles per hour. So strong we had to quickly seek shelter inside. Look at that. Those are the wind gusts that we have seen and that officials have warned about. This is absolutely a mind blowing event that is unfolding right now. The monster storm inched along at times, just one mile an hour. I don't know if you can see it but I want you to listen to the wind and the howl of the wind as it goes by. We've seen large pieces of debris flying in the other direction. Alright and it looks like we've just lost power. We're on the third floor and the water is pouring through the door. Meanwhile, outside, the furious rain and intense storm surge flooded streets. Uh this is very deep water. Reporter: This video shows the water reaching a second floor apartment sweeping up the stairs and slamming into the window. And in this home, furniture bobbing in the water. Jack petard of Kentucky sent us this video from his home in the Bahamas. Look at the roofing, gone. And I'm worried about destruction next. Look at all the siding torn off this house. Reporter: Some residents became trapped. Water is everywhere. Everything is just in ruins. One mother pleaded for prayers on Facebook. Everyone please pray for us. Please my baby is only four months old please pray for us. Reporter: The roof ripped off her apartment building. She took shelter with other families. Is there a safe place we could be right now. Reporter: As the eye of the storm moved over the islands, our team witnessed people practically being swept away. Swim this way. Alright, we got them. Reporter: They were rescued just in time. They later told our ABC affiliate WPLG that they were terrified. We were happy to be saved. The house was getting flooded up to 10 -- I don't know, up to five or six feet. Reporter: Once it was safe to go outside, our team surveyed the damage. You can see the power of this storm. Cars littered across the island. Homes reduced to piles of debris. The red cross estimates that more than 13,000 houses have been damaged or destroyed. That is equivalent to about 45% of all dwellings on abaco and grand bahama. Tim aylen, a bahamian journalist, had to flee his home. He and his daughter waded through chest-high water to seek safer ground. This is what the grand bahama airport looked like St a few days ago. And this is what it looks like now. In the town of marsh harbour, we're with authorities as they go through these destroyed homes looking for both survivors and those lost to mother nature. We head to a hospital that has turned into a makeshift shelter. This is the clinic where a lot of the injured have been treated but also there's a lot of family members and just people here occupying the hallways. Every hallway is full. They have already treating more than 150 people. And they don't know how much longer they can continue to operate. Government officials say there are areas first responders cannot reach. The us coast guard has been dispatched to rescue survivors at least 47 so far. You can see a United States coast guard helicopter behind me. And another military aircraft helicopter. They've been running patients in and out they've been rescuing from the abacos. Reporter: States of emergency have been declared from Florida all the way to Virginia as tropical storm force winds have begun lashing the east coast. The storm has now weakened to a category two, but the wind field has gotten larger. The next couple of hours is going to be the critical time for any of the surge that happens on the east coast of Florida. Reporter: Gio Benitez is in new smyrna beach Florida. We're actually on a boat dock right now. It's high tide but clearly a lot higher than usual. Now we're looking at the possibility of that storm surge meeting high tide. That's the concern. Flooding is very likely. Reporter: More than one million people have been ordered to evacuate. It's important that residents heed those calls, get out now. Reporter: Rob Marciano is in Melbourne beach Florida. The center of Dorian now just a 100 miles due east of us. A tornado warning has been issued for our county. The tornado threat is going to be ongoing tonight. These winds are only increasing. Reporter: Earlier today, my colleague Kaylee Hartung was in Jacksonville, Florida at one of the many staging areas for the National Guard. There are 250 of these multipurpose vehicles at this staging area. It's not even the largest they have in the state. These vehicles, they can do everything from transport troops and supplies to performing water rescues in places other vehicles can't go. We are ready to bring in logistical support, communications support, high water rescues support, security force missions support. Reporter: In Charleston, South Carolina, business owners are bracing for the worst. Laying sandbags down and boarding up windows. ABC's Megan tevrizian spent time with Allan Vandall, the co-owner of Tommy Condon's Irish pub. They're planning to stay open through the hurricane but taking precautions. Allan, describe how high you think the water is going to be outside here? I think it's going to get right around here. We're going to have sandbags to about here. We're going to gorilla tape the inside and outside seams of the door and hope for the best. Reporter: Hospitals in the state are racing to beat the storm. Trying to move as many patients as they can to higher ground. This patient is on his way in an ambulance to a Virginia hospital two hours away. We have 10 patients that are confirmed to leave and there will be others today. Reporter: But not everyone is healthy enough to be moved. David Eason is fighting a serious blood infection and will ride out the storm in his hospital bed. If they tell you to pack up and go, go. If you can. In my situation I can't. Reporter: Back in the Bahamas, those who now call this unfamiliar place home face a long road to recovery. Reporter: Our thanks to Marcus for that report. Joining us now is ABC news meteorologist Greg Dutra. Greg, we've seen the harrowing devastation in the Bahamas. The storm is weakening but that westerly shift means it could still pack a punch along the east coast as it heads towards the Carolina coast? The main impacts will be felt Wednesday into Thursday as it rakes very close to the outer banks of North Carolina and precariously close to even Charleston. Even if it doesn't track over land there will be massive effects. And even for the low-lying areas, that could be dangerous. The king tides, which are normal astronomical high tides this time of year, and Dorian effects, four to seven storm surge coming in, waves on top of that and six to ten inches of rainfall on top of that, it is going to be dangerously close to records. We will be keeping a watch. Coming up next for us, from
This transcript has been automatically generated and may not be 100% accurate.