How do you get inside the hidden chambers on fy_buzzkill?

How do you get inside the hidden chamber(s), behind the escalators, on fy_buzzkill I'm playing version 1.6.

Edit: I noticed a couple of players were able to crawl inside the escalator, camp and shoot anyone who lurked in that area from inside.

Normally, the escalator throws you in the air when you step, walk or run on it. However, a player asked me to crouch+move onto the escalator; when I did I went straight through the escalator. There isn't any ammo or easter egg there but it is a very, very good place to camp.

Now, next day I tried to repeat the trick over and over again (multiplayer and local) but failed. I need "steps to reproduce the behavior".

Here is screenshot in overview mode:

Move around here and there so that some of the wall and other textures disappear which reveals the space for camping:

As @Nitrous Oxide said above. It is not a "Secret Room" per say - It is a secret glitch that players exploit to get kills from un-expecting victims. Its a cowards paradise.

If you crouch and walk at the correct angle into the corner of the "treadmill" you can essentially "slip" into the underside of the ramp where you can see through the ramp, clear as day, and fire through it to attack enemies. I haven't played on this map in a long time but if I remember correctly people are unable to shoot through the ramp to hit you while in there. I hope this helps out! Happy Camping!