Transcript for Hurricane Irma brings devastation to the Florida Keys

All right, Steve, stay safe there. The massive scale, hurricane Irma first made landfall as we said in the Florida keys. Just after 9:00 A.M. Sunday and it hit hard. The emergency management director fears it could cause a humanitarian crisis. The entire area under mandatory evacuations, residents still barred from returning and Amy robach traveled through the night to get to nearby Florida city. Good morning, Amy. Reporter: That's right, George. Good morning to you. We got up very early and drove for about an hour from Miami and we got to this point. Yes, near Florida city where there is a police roadblock. No one who isn't on official business can get through past this point. This is the point of U.S. 1 where it narrows into a two-lane highway surrounded by water and so officials have to get in there, clear the debris from the road, assess the damage and make sure those bridges that take you to key west are sound and safe before they will allow residents to return home. This morning, we are getting our first glimpse at the devastation in the lower keys. After Irma stormed through with 130-mile-per-hour wind gusts. Boats on the roads. Cars buried under sand. Store windows blown out. Houses barely standing. Debris everywhere. Residents advised to boil drinking water. As Irma came roaring in, these two storm chasers tried to measure the wind speeds unable to hold their ground. Transformers igniting. Trying to drive from Miami to the keys overnight, we got a firsthand look at the devastation Irma left behind. It's a tree down right there. Wow. None. The streetlights are working. All the power is out. So everyone has to drive very carefully. Thankfully there aren't many people on the road at 3:00 in the morning. In key largo David Kay choosing not to evacuate documenting Irma as she moved in watching his property engulfed from the storm surge. We're doing all right. Reporter: This morning the painful process of cleaning up. That's our sign. That's our tree. Reporter: Remarkably, as you just saw there the only insight we have into the actual damage in the keys right now is from people who are able to still use social media or Skype or have some sort of connection because no officials have actually gotten in there until just now this morning we saw a huge convoy of army trucks going in with supplies and equipment for the people who are there and certainly to clean up whatever needs to be cleaned up and there is significant damage as we can see but in the meantime, a lot of residents are lining up trying to get in and the police are having to turn them away. It is certainly an unknown what's inside. We talked to a group of Monroe fire rescue and said they had no idea what they would find once they got in. The unknown, Amy. Thank you. We know hurricane Irma has been so devastating.

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