This PS player fell down there within the first minute of the round and was stuck during the whole round. I haven’t tried getting out of there myself, so i’m actually not sure if it’s impossible to get out, BUT we lost our 4th teammate because of this. xD
Area: At the top of the mountain where the elevator is, behind the platform wall on the opposite side of the elevator itself.
If you can get out from that cavity then maybe this picture below might be true!