Is this the bunker underground where the roof falls down on two enemies heads? and then when you come out the other side enemies charge at you but are killed by your men coming over the top????? - and lots of gun fire comes from the right hand side through a fence??
I f*cking hated that bit but it is possible, heres how I did it:
As you pop out of that bunker (come out the left, not the right hand side) enemies will run at you - try to ignore them (your men should take them out, maybe shoot the one straight ahead of you) because basically you want to throw your smoke grenades as quickly as possible - one in the middle of the open area in front of you and as many as you can toward the horizon. This is because if you get to the ridge in front of you there is a trench: if youve smoked up the place they will own you, but if you don't you will be shot from the right: so you want as many of your men to survive as possible to act as a distraction. *you will not be able to kill anyone until you are in that trench* - hence why you keep being killed from 'somewhere'.
basically make it so the entire area is smoked (i did it with 3 smokes) and then charge in a straight line from the left door up to the ridge, as you fall into the trench face right and fire: i think there are around 3/4 men. (there should be one man behind you -on the left- in the trench but hes just around a little kink in the line so you should be ok)
I feel your pain, believe me, but enjoy the end of D-Day when you retreat
- or the next level where you have to clear buildings a - g ...... (that level is at least fun, d-day pissed me off)
Hope that helped