Nightly News | March 01, 2013
>>> now to the town of seffner, florida , where last night the earth opened up as it does increasingly and thousands of times every year in this country. this time it swallowed a 37-year-old man as he slept in his home. our report tonight from nbc's gabe gutierrez.
>> reporter: in his bed one minute, gone the next. jeremy bush says he heard a loud crash, then his brother jeffrey screaming late last night at their home near tampa. he jumped into the massive hole in a desperate attempt to rescue his brother.
>> and i couldn't get him. all i could hear -- i thought i could hear him screaming for me and hollering for me to help him. and i couldn't do nothing.
>> reporter: remarkably, outside, the house looks like nothing happened. but inside --
>> the open hole is about 30 feet in diameter. and it's about 20 feet deep.
>> reporter: while sinkholes, like these in ohio, minnesota, utah and this one in guatemala often grab headlines, they're most often reported in these seven states. texas, alabama, missouri, kentucky, tennessee, pennsylvania and they're especially common in florida , where more than 15,000 sink holes have been recorded. last may, this huge hole swallowed an entire backyard near orlando. last june, another destroyed an entire home. while experts say many things can cause them, in florida , it's a domino effect . the state's sandy soil, on top of clay, supported on a deep layer of limestone, can suddenly collapse, due to a dramatic shift in florida 's unique underground rivers.
>> florida essentially sits on a system of caverns that are filled with water to some degree. and as that water moves up and down, it erodes those caverns and from time to time they collapse.
>> reporter: back near tampa, engineers are trying to explain what happened here, trapping a man in his own home without warning. gabe gutierrez, nbc news, seffner, florida .