Call of Duty 4 in Video Gaming Posted November 19, 2007 Yeh I've found the ticket booth. It's indestructible, and blocks the grenade blasts. You just need to try and keep the guys down who face the doorway so one doesn't land in it. The chopper arrives and they say you have 30 seconds. I made a dash for it, but perhaps at this point the enemies stop respawning. Perhaps 15 seconds of sniping would be well invested. Cheers though, at least you've given me will to try it again.