The Devil Below (2021) on Netflix

Plot summary

Shookum Hills, a coal town in the Appalachian Mountains, has been kept off the maps since the 1970s, when its population disappeared; the vanishing is blamed on an underground coal fire that opened sinkholes around the town. Darren, a scientist, believes a rare mineral started that fire, and he joins Arianne, an adventurer, and three other researchers, Shawn, Terry, and Jaime, on an expedition to the mines. At a store, the proprietor says the name means nothing to him and tells Arianne to head back. As they drive off, he alerts someone that there is trouble. A car follows them; Arianne loses it, and the group climbs an electric fence to the abandoned mine, where a sinkhole sits behind an improvised electrified barrier.