Can you discuss the setting for Dead Money?

Dead Money is set in the Sierra Madre, an opulent and extravagant resort that was supposed to be the greatest casino in the west – except that it never opened. Bombs fell before the gala opening, and the Sierra Madre froze in time, its state of the art security system locking the place up tight. Nothing could get in, and none of the guests could escape. Years passed. The climate control and air conditioning system within the facility began to spit toxins into the surrounding city, causing a slow cloud and haze to form over the area - which proved lethal to anyone who tried to explore the city. Only a mysterious group called the Ghost People survived to call the city home, trapped inside what appeared to be hazmat suits and never speaking to their victims... only capturing them alive and dragging them away to the depths of the city deep within the Cloud.​