Sinkholes: common, costly and sometimes deadly

Story highlights

Central Florida is particularly known for sinkholes

The state lies on limestone bedrock and often sees the phenomenon

Florida property owners filed 24,671 claims for sinkhole damage from 2006 to 2010

Florida sinkhole claims cost insurers $1.4 billion in that period, state Senate report says

Sinkholes, like the kind that swallowed part of a resort near Disney World in central Florida this week, are more common than you might think.

What causes sinkholes?

Many sinkholes form when acidic rainwater dissolves limestone or similar rock beneath the soil, leaving a large void that collapses when it’s no longer able to support the weight of what’s above, whether that be an open field, a road or a house. These are called “cover-collapse sinkholes,” and it would appear this is what’s happening in Florida, where the ground beneath the home suddenly gave way.

Where do they happen?

Sinkholes are particularly common in Florida, which rests on a nearly unbroken bed of limestone, according to the Florida Sinkhole Research Institute.

Do all sinkholes collapse so dramatically?

No, some merely cause the ground above to sag, or result in small ponds or saltwater marshes, the Florida Department of Environmental Protection says.

How often do they happen?

There do not appear to be any solid numbers, but the Florida Senate Committee on Banking and Insurance reported that insurers had received 24,671 claims for sinkhole damage in that state alone between 2006 and 2010. That’s an average of nearly 17 claims a day, just in Florida.

How dangerous and costly are sinkholes?

Deaths and injuries from sinkholes are rare, but certainly not unheard of. For instance, in 2012, a 15-year-old girl died when her family’s car fell into a Utah sinkhole, according to media accounts. But the holes are enormously costly. Insurance claims submitted in Florida alone between 2006 and 2010 totaled $1.4 billion, according the Florida Senate report.