Yeah Florida's aquifer runs underground all over the state, we're full of underwater caverns and sinkholes. Way back when I was at FSU we had professors that had mapped miles (held a world record IIRC) of underground caverns connecting lakes all over the place. I actually got college credits learning to scuba dive.
When I was a kid, I remember folks studying the lakes around town dropping bright dye in one, only to have it pop up in other lakes a ways off.
I'm so glad we live on granite.
My dad's family is in Orlando, and I was down there when the Winter Park sinkhole opened up. It was pretty amazing -- slow enough that there were no fatalities or serious injuries, but fast enough that some houses and cars were lost. The neighborhood swimming pool was cut in half.
I think, though I'm no geologist, that Florida is most vulnerable in times of prolonged drought -- when the aquifer recedes, the water that isn't there leaves a void. The soil is all porous and sandy, so it sinks. The technical term is Karst topography; you also see it in Minnesota, the "land of a thousand lakes," where the freeze-thaw cycle forces open cracks in the rock.