I visited gran'ma in the hospital the other day and confirmed what I had often heard: there aren't any 4s in Japanese hospitals.
Some people may claim that the Japanese are superstitious, pointing out that the number (四, shi) sounds like death (死, shi) in Japanese. Incidentally, the same is true in Korea, Taiwan, and Vietnam, countries which like Japan had incorporated this tetraphobia along with the Chinese writing and numerical system well over a millenia ago. No, I think the omission of "four" in hospitals today is influenced more by a desire to avoid upsetting or discomfitting patients than superstitious claptrap.
While I was in Hawaii a few weeks ago, I noticed that our fourteenth floor condominium was actually on the thirteenth floor. When I pointed this out to my wife, a wild-eyed man riding in the elevator with us said it was because the building had been built by Freemasons. It was the first time I'd heard that and have since Googled it to see if there's anything to it. (There is and there isn't.) At any rate, I'm still not convinced. Most likely, the developer didn't want to take any chances that there might be triskaidekaphobes among his future clients. Why make things hard for yourself?