There are many news stories this week about a 64 year old woman fell into a sinkhole in Pennsylvania. The earliest photos show a small hole, maybe two to three feet in diameter. The rescue operation immediately starts to “dig out” the hole using a large backhoe. The hole is now very large.
This is probably a dumb question, but why are they digging it out? It would seem that would make the situation worse, as dirt would inevitably start falling into the hole and trapping her further, and the walls would collapse. In my mind, it would seem the best approach is to (at least initially) lower a rescue person into the hole (using a crane or hoist) while being careful to not disturb the dirt.
According to the TV news report in your second link they increased the size of the hole to make it easier to get to the victim. Presumably, the ground a few feet away from the hole itself is more stable than where the hole is, so they can now move people and equipment down the hole more safely. They said the hole was 30 feet deep, so I don’t think enlarging the hole endangers the victim, assuming someone is actually down in the hole somewhere.
I’m not a rescue person of any sort, but the pictures made it look like there was a larger chamber or tunnel just below the opening. I would think that this would mean there’s quite a bit of overhanging dirt and material that could collapse as the rescuers work around the opening. Widening the opening by removing material seems like a good idea to reduce the likelihood of further collapse.
Although I’ve trained in various SAR modalities (lowland, mountain, desert, swiftwater) I haven’t been trained in caving rescue, but the primary rule in any rescue operation is to not put rescuers in unnecessary jeopardy or an environment with uncharacterized hazards because you don’t want to create more victims requiring rescue. Lowering a rescuer into a ‘sinkhole’ that has not been stabilized is a very dangerous thing to do for a number of reasons, including potential submergence, collapse, toxic or heavy gas, or just becoming entangled with buried lines, roots, et cetera, and without stabilizing the entry could result in hazard to both the rescuer and victim.
While I have not done cave rescue (and only very limited experience with spelunking), I have worked as a ‘beater’ in grain elevators, knocking sticking corn and soy from the sides while the the grain is being evacuated. While the loaded grain is pretty compacted, once it starts being drawn from the bottom it can create a powerful funnel, and it is pretty easy to suddenly find yourself stuck down to your waist or deeper if you aren’t careful to stay near the wall and be attentive to how the grain is flowing, and once you are that deep there is just no way to pull yourself out; they have to stop the elevator and then dig the beater out lest they get pulled all the way below the surface of the grain and asphyxiate (which is not unheard of). And dried corn and soya grains are pretty coarse and don’t really create suction. If a rescuer were trapped in compacted moist soil, or worse, a slurry of mud up to or above your waist they’d essentially be stuck, and trying to pull the rescuer out of that from a harness would basically tear them in half.
True sinkholes (dolines resulting from suffosion of the soil into substrate, dissolution of underlying karst structures, or collapse of natural caves, voids, or underground rivers) are often quite unstable and can grow rapidly surface extent, so it may be difficult to even position rescuers and surface support to enter without putting them at risk. Given where this is at geographically (in Pennsylvania coal country) I strongly suspect that this ‘sinkhole’ was precipitated by subsidence of an abandoned mine shaft or other digging. This kind of collapse isn’t quite as likely to grow as widely and unexpectedly as a natural doline but it may be quite deep, and can create a frustrum of unstable material which can collapse, creating a funnel that would essentially suck down a rescuer if they were lowered down deep when the collapse occurred. This could also pose additional dangers as mine shafts can fill with water into which has leached toxic compounds or collect with gases or flammable dust. Lowering in a rescuer to perform an exploratory search would present grave risks.
I was in Colorado Ground SAR. This is the number one rule.
Not sure of the womans condition, or if she is conscience or not. I think though a crane could come in, stay far back from the hole, swing over a SAR person and gently lower them into the hole to rescue her.
Dangerous? Yes. And sort of breaks rule #1 above. You really can’t be an arm chair quarterback with this stuff. Ya have to be on site.
I guess they have lowered cameras and communication down, but haven’t found anything. Digging more sounds like a recipie for a bigger collapse.
As a firefighter I’ve taken trench awareness class which sinkholes qualify, which is exactly what it seems like. To make us aware of a certain situation that to an untrained eye may look like an obvious path to rescue that has the potential of causing a much larger incident with potential loss of life, limb and equipment and in general making the situation much worse. Our training only goes as far as recognizing such a hazard is beyond us and to call in a special team which may use methods like used here, or dig a nearby hole and start trenching towards them coffer-damming it along the way as they advance.
This story is super, super sad. She was looking for her cat, her 5-year-old granddaughter was left in the car. Just swallowed up by this sinkhole. Not cool.
I watched all of this press conference a couple hours ago. TL : DW - She fell about 30 feet down, and 10 feet outward when she landed on the “Hershey’s Kiss”, a conical mound in the sinkhole, and probably died immediately or very quickly. The community was also great, regarding the support given to the rescuers, and he placed the owners and staff of the adjoining Mary’s Restaurant near the top of that list. Incredibly, this property does not appear to be at risk of subsidence. He also requested privacy for the family, and further information will be issued when and if they have it.
(Of course, as a cat lover, I do wonder if Pepper ever came home.)