There is an awesome book called “Dead Mountain” about a group of Russian skiers who died mysteriously in 1957 or 1958. This sounds similar (no pun intended).
The authorities couldn’t figure it out: while it was freezing and on a snowy mountainside, all seven were found outside their tent, mostly undressed, like they had run out in terror. No sign of struggle in the tent. No signs of violence.
The writer re-experienced the whole hike and when he camped on the mountainside at the same spot he found the wind coming through a particular alignment of the mountain generated an outrageous sound AND pressure! He and audiologists discovered that in fact the sound/pressure can drive you insane. They concluded the seven literally were driven nuts and ran out of the tent on their own.
That they were in a militarily restricted zone which Soviet forces used to test weapons has absolutely nothing to do with it ... Penalty for intrusion into such zones was death on the spot.