how do you know a tunnel is there with stairs? after all you say its 80ft deep.....and you cant see that deep !!
The topic here is about minimizing the effects of poison gases not the way how we dig our hole. If u wanna know Mr. Janner it's not only a vertical straight digging. We follow directions based on the stone signs and soil layers as well. We know it because it's the only hardened layer discovered after removing the soft layer which is made of sand, gravel and soil. Every flight of stairs is measured 1 meter which makes it easier for JIA to hand over the valuables from soldier to soldier until it reaches to wherever they want it to place or hide. Well, let's back to the topic which is on poison gas.
wow what a arrogant person you are!
you mentioned it in your post so its there for us (the public) to ask inquire or comment
so get down off your high horse and be civil.
personally i reckon its bologny but there we are, my opinion.
as for the gas, wear a gas mask ffs !!!
have a nice day digging big holes