1). Room: Long, dark hallway located in Zone 2.
After walking briefly through the hallway, the player will suddenly hear muffled screams as a partially burnt hazmat worker comes barreling down the hallway. He falls down and slides to the player's feet, clearly dead. Suddenly, the player hears 106's laugh and sees his eyes in the darkness, before he emerges from the shadows and chases the player.
2). Room: Small observation hallway that is above and perpendicular to a lobby of sorts.
There you'll see a janitor huddled next to a mop bucket and some corpses. Then, you'll see a light turn on above an elevator towards the far side of the room, and the janitor will get up. He'll say "Ah, about damn time!", before the doors open, letting out the MTF squad. The following dialogue occurs (or something roughly similar)
After walking below the hallway the player is located in, they'll exit through another door as the announcement that the MTF have entered the facility plays.
3). Simple hallway, probably in zone 1 or 3.
You'll hear some metal sheeting rustling above you, and stone scraping. After a couple of seconds, the vent lid on the ceiling will bust open and fall to the ground, before 173 comes falling down too, with a huge concrete thud.
4). Office room, zone 3.
You'll hear some people whispering before entering the room (like how you'll hear the suicide guard). Things like "Quiet, I think someone is coming. ' 'Are they here to rescue us?' 'I don't know, quiet down." Then you'll hear 106's iconic decomposing sound. If you enter the room, you'll see several scientists panicking behind the glass panes of a conference room, as a huge sinkhole starts to appear below them. While they scream bloody murder, the room's environment will become so violent that the windows will glaze over as they melt, and will eventually become opaque. The door will also refuse to open. You can continue past the conference room to a door on the other side of the room.
5). Simple hallway, zone 1 or 3.
The lights in this room will not be lit, and it'll nearly impossible to see. After approaching a few steps, the lights in the room will flicker on with a jolt, illuminating a mangled corpse, and maybe some evidence of how it became so.