Published: Dec 27, 2013 6:37 AM EST

TALLAHASSEE, Fla. (AP) - State geologists already have been to 30 sites and mapped about 50 sinkholes as they begin to plumb the depth of the state's vulnerability to ground collapse.
The Tampa Tribune ( reports that Florida received a $1.08 million federal grant for a three-year statewide study, starting last month with a pilot study in Columbia, Hamilton and Suwannee counties.
The result will be a detailed, multi-layered map that shows where sinkholes are most likely to form, but doesn't predict where and when individual sinkholes will occur.
In February, a Seffner man died when a sinkhole opened under his bedroom as he slept.
Sinkholes are common in Florida because of porous rock, such as limestone, that stores water underground.
Information from: The Tampa (Fla.) Tribune,

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