i believe i know what happened! when shutting down the facility at the console to the left there was a door, i didnt go in it at first cause i went to shut down the facility first and ended up not being able to go in there after, i believe you were supposed to go in there before shutting down facility, but because the console had the "!" above it i think most people shut down the facility and either never knew the door was there or shut down the facility and locked themselves out of it.
this is what i think atleast and might not even be the correct thing