When you first start the game, go in the elevator. When the doors open, enter the room to the left. You will find a crowbar. Hit the soft drink machine and get out of its way before it crushes you. After it falls, you will notice some gas spraying out. Jump over the machine and crouch down. Go over to the little hole in the wall at the back of the machine. Press E (Use)to shut off the little valve and the gas will stop spraying. Go in the hole, turn on your flashlight, and climb the ladder. Keep going and the floor will fall. You will now be in a secret room with shotgun and pistol ammunition.