I recall the whole Mandalay bay situation and recall talking to someone who said that it isn't as uncommon as one might think. especially in areas where the soil is sandy. In Florida for instance I heard that they have occasional problems. I saw a special about an airport that was built on land fill in Japan where it is still sinking.

Without going into too much wordiness the problem is when the weight of a building compresses the soil around it. Engineers usually do some extensive calculation to figure the amount a building will sink before it compacts the base under it and will often build it's foundation above the ground with that in mind. It doesn't always work. Sometimes the soil, or sand, has more compactability than they anticipated. The airport in Japan, if I recall correctly, is still sinking but the building was built for that eventuality and they had to add more steps on the stairs going into the basement. It was built on hydrolic jacks so that as the foundation sinks they add blocks under the jacks to keep the building level and at the right height. When the special was filmed the aiport terminals foundation had already sunk more than about 2 or 3' more than they had anticipated. The stairs leading to the basement no longer came all the way to the floor. They had to build more steps. An added benefit of this ERROR? was during a bad earthquake a few miles away in Kobe, one of the worst in history, the airport only had 1 broken window while the city was almost destroyed. The soil structure and automatic jacks were able to keep the building from shaking too much, or something like that.

In the case of Mandalay bay, the building was sinking unevenly. I read that when they went in to put up finish carpentry in the rooms, they found that certain components were not fitting. While 2 equally long pieces of trim, say the verticals in a door way, were brought in, one would fit but the other would be too long or short... Also the entrances from the garage to the building didn't match up all of a sudden as the building was sinking but the garage wasn't. Anyways, I recall that what they did was found the areas of sinking and INJECTED concrete in those locations to stop the sinking. That is what is commonly done in some of the Florida situations I had heard of. I recall a story of a pool that was sinking and they came in and injected some concrete under part of the pool deck and under the pool to stop the sinking.

I would really doubt that Luxor would have to be torn down. If it is in fact sinking, Not surprising considering proximity to Mandalay Bay, Could be some geological reason for the soil or sand conditions there. I would think that similar engineering could be used to slow or stop it. I don't know how buildings are built in Vegas but I do recall watching some in FLA. Near the Gulf of Mexico. They pound pilings into the ground until they rest on Bed Rock. Then they build the buildings on the pilings. I would imagine that in LV they probably do something similar, maybe pouring footings? or something. Whatever those supports might would that be where they would need to inject concrete under them to raise that part of the structure?