Diamond deposits were discovered there in the 1950s, at which point the USSR proceeded to thaw open the frozen ground using a combination of jet engines, explosives, and presumably high-volume Russian vodka. And then they just kept digging and shoveling out shiny rocks for the next 40 years. The hole is so big, in fact, that it's said that helicopters can't fly over it because they'd be sucked in by the force of the downdraft. We don't wanna know how they determined that.
There's at least 30 UFOs stuck down there.
So, in case you were wondering who the hell digs a giant hole next to a town, it was the other way around: the town was built around the hole during its excavation to provide a place for the workers to get drunk without risking falling into the Earth's core. The diamonds extracted were then taken to Moscow and used to construct a giant la- uh, sold. They were sold. Yes. No lasers here.
The laser floats above us and turns towns into craters.