NBC晚间新闻 佛罗里达发生地陷，无人员伤亡（在线收听）

Florida sinkhole survivor: ‘I’m still in shock’

佛罗里达沉陷幸存者：“还是很怕”

Rescue teams evacuated guests from a resort in Clermont, Fla., before the building sunk into the ground. Geologists aren’t able to predict when a sinkhole will occur, but they do know what causes them to appear. NBC’s Kerry Sanders reports.

营救队从佛罗里达州克莱蒙特的一处度假胜地解救客人，酒店即将塌陷。地理学家不能预测何时发生塌陷，但是他们知道造成塌陷的原因。NBC的Kerry Sanders报道。

Good evening, I'm Lester holt sitting in tonight for Brian. What an incredibly close call in a resort near disney world when the ground literally opened up beneath them as many slept. What it looks like from above the scene now in Clermont, Florida , where a massive sink hole opened up overnight clapsing much of the resort structure. More than 100 people were forced to evacuate. Some under harrowing conditions, remarkably no one was killed. NBC's Kerry Sanders is there with late details. Kerry, I assume you're on firm ground right now, but how big a danger area at risk is there?

reporter: Well, good evening, Lester. They've moved up three city blocks fearing the sinkhole would continue to grow. The problem actually begins about 20 to 100 feet down where there's limestone. Rainwater goes through the earth and hit that limestone and it can cause it to dissolve. That is a recipe for disaster.

We need to know what room everybody was in.

reporter: It was shortly after 3:00 in the morning, Maggie Gammery started her camera phone during the chaos. She says it came without warning while on vacation here with family and friends from Virginia. She heard a single window pop its frame, then another and another. At first she thought it was someone in a fight.

Things flying, like glass flying. People jumping out of windows, luggage flying out of windows, people trying to salvage what they could.

To me, it sounded like popcorn popping. porti pop, pop, pop.

reporter: A security guard on patrol then began to run from unit to unit in all evacuating 105 tourists here on vacation.

There were people sleeping. I literally had to wake them up and tell them get out of the building.

reporter: Why do sinkholes occur? in Florida, the state sandy soil sits on top of clay, and that is all supported on a layer of limestone. Limestone is like a strainer. The water migrates down and it hits Florida's underground rivers, but when there is too much rain or a drought it can create a void like a balloon with air. As that void gets bigger, the earth on top becomes too heavy, and the balloon pops, causing a catastrophic event--a sinkhole.

Geologists say they know when conditions are ripe for a sinkhole, but like an earthquake, they cannot predict when or where one will open up.

The open sinkholes may open other sink holes .

reporter: Trigger them?

Yes, it's possible. Because these are connected underground, again, by the same limestone cavity and cave structures.

reporter: 20% of the nation is susceptible. other likely locations for sinkholes, Pennsylvania, Tennessee and Utah. In Florida in March, a sinkhole 30 feet wide and 50 feet deep opened up swallowing 36-year-old Jeff Bush from his bedroom. His body was never recovered. Here in Clermont, Florida, 15 hours later, survivors are still anxious.

I'm still in shock and I'm just very, very thankful.

reporter: Lester, the sinkhole right now is about 100 feet wide about 15 feet deep they guess as looking down there. The likelihood of something like this is being struck by lightning, which, as we know, can also happen.

We've seen them before, Kerry. It's sounds like a bit of a guessy game. What can home owners do, what they know about moving into a neighborhood, whether there is a risk?

reporter: Well, they can actually get a geological survey using ground penetrating radar to look down there. But this is a situation that's constantly changing depending on the rain situation. So you can find those bubbles, but even the bubbles don't necessarily tell you that there is going to be a catastrophic collapse. One thing everybody needs, sinkhole insurance.

Alright, Kerry Sanders tonight, thanks.