This is like a nightmare. But it’s real.
A Florida man lying in bed fell into a sinkhole that opened suddenly beneath the bedroom of his suburban Tampa home, calling out to his brother for help as he fell, a fire department spokeswoman said Friday.
Five other people, including a 2-year-old child, escaped from the home. Rescuers had to pull the man’s brother away from the edge of the sinkhole as it ate away at the ground under the home…
The sinkhole is naturally ocurring and appears to be about 100 feet across, based on estimates made by engineers using radar, and it may be as deep as 50 feet, authorities say. It’s not visible except inside the home.
The man is assumed to be dead, likely crushed or suffocated, as equipment was not able to detect signs of life. This is a harrowing story. Florida is sinkhole central and every year there is considerable damage to homes, roads and structures caused by sinkhole collapse. Having had extensive experience with sinkhole geology, I have seen how insidious these hidden hazards can be and how difficult they are to mitigate.
Sinkholes are a hidden danger. But rarely do people die from them. There are other cases of house collapse leading to death, here (though this is more of a landslide than sinkhole). This man died while apparently investigating an existing hole which collapsed around him. A woman died when the car she was in landed in a hole in the roadway. A whole family perished into a sinkhole in Witwatersrand, Africa due to gold mining.
The surface manifestation of a sinkhole begins long before as void spaces in the limestone bedrock. As soil and surface material migrates into these voids, the hole itself “migrates” upwards. Eventually the surface collapses into the void beneath. Here is a factsheet [PDF] (from Pennsylvania which also has sinkhole hazards) that explains basic sinkhole formation.
What is surprising in this case is that there seems to be no hint that a collapse was imminent. Often there are at least some ground signs. I will try to follow up on this story to see if they report any triggers for this collapse.
What can you do to protect yourself in a sinkhole prone area? Check existing geology maps for historic sinkholes. (Maps for Florida) If they were mapped once, they will often reactivate again. Buy sinkhole insurance. It is not included in your normal homeowners policy and is inexpensive in most states (Florida may be problematic). But note that insurance only covers the structures. If the hole happens in your yard, you may not have any redress. Without this special insurance, the structure if affected will be costly to repair and lose considerable value due to the hazard.
This link contains a video of the brother of the man who tried to save him and had to be saved himself. Quite heart-wrenching.