This version of Las Vegas Skyline was never officially released. Actually in the history of LEGO only 2 sets were actually cancelled prior to release and this happened to be one of them, the other was 21000 Sears Tower. This original 21038 Las Vegas set included the Mandalay Bay Hotel in the skyline. The set was redesigned in response to a mass shooting event in October of the previous year at the Mandalay Bay Hotel, replacing it with a different building, the Bellagio Hotel in set 21047.