Collapsed tunnel (the lost miner quest)

[Sandrea9]

Does anyone know where entrance exactly is?

[OMG its WEE]

Find the long set of ladders (broken off at the bottom by a collapsed elevator)
climb halfway down them...

[alan]

i have found the wall with the dynamit but i cant blow it away? i searched the hole area o the old man but nothing to find?

[Olipool]

I don't remember that well but the Wiki says:

Keep going forward and eventually you'll rejoin the tunnel. After a few meters, on your right, you'll see a wall with dynamites. Hit it with the torch or trow a Molotov. The fuses will start sparkling and you'll have a few second to step back before the blasting. Now the way is open to access the cavity in which the miners were trapped.