TODAY | May 07, 2012
>> a large sinkhole that's opened up in a florida neighborhood and forced at least one family to move out is threatening more homes this morning. nbc's kerry sanders is in wind mere, florida , with more on this story. kerry, good morning.
>> well, good morning, ann. sinkholes are not that rare, because they dot the central florida landscape but this one is a little bit different, because it appears to still be growing. now we don't know how deep it is so i've set up a little experiment here. we've got a weight and we've measured the rope out every six feet, as i toss this out at the water take a look at what was, and what is. what is now a giant hole in the ground was just a few days ago a backyard playground. where sand bill cranes paraded in the afternoon sun. a spot of ceron ter disappeared when the earth began to swallow the yard.
>> what's your emergency?
>> there's a gigantic hole in my backyard.
>> reporter: in that first call to 911, lou went from incredulous curiosity to full-on emergency evacuation .
>> everybody out of the house. come on, come on, everybody out of the house.
>> reporter: denise was the first to realize something was wrong as the hole took down four 30-foot tall oak trees .
>> she woke me up and said lou there's a hole in the backyard, and i -- i told her it's probably a warthog, i don't know why i said warthog.
>> i said, no, it is a hole.
>> she was shaking. and then when i saw her shaking, and the panic in her face, we both ran downstairs, and as we ran down, it was collapsing. the ground was collapsing into itself.
>> reporter: the family evacuated and emptied their home. just in case the sinkhole continues to grow. which is a very legitimate concern.
>> police said it was 1500 feet across and 200 feet deep.
>> reporter: in 1981 , in nearby winter park , florida , a sinkhole swallowed a car dealership, a public swimming pool, and a portion of the roadway, all in a single day. geologists say these surprise openings are created when florida 's sandy soil, on top of clay, which is all supported on a deep earth layer of limestone, faces a sudden and violent collapse. the catastrophic event is off be the result of a dramatic shift in florida 's unique underground rivers. in this case experts say one of those rivers likely started to dry up, because of this year's record drought.
>> if you lower that water level then all of a sudden you leave space where the ground on top can actually sink down into it, hence the sinkhole.
>> reporter: so there is such a thing as sinkhole insurance, but it's not really a popular thing to people to buy. it's not mandatory. now we've measured this and i've pulled this back out. it's about 30 feet deep. that's assuming our weight didn't actually hit one of the trees that was sucked down into the earth. yes, as you saw at the bottom here because this happened this weekend. this is a cinco de mayo .
>> kerry sanders giving us something to smile about. it's nice to see the family also having a sense of humor about this. thanks so much this morning.