Unless someone has personal experience in this and it is not hear-say, I would call the school/dean and explain your case.
As for my opinion, I think that almost any school can defer your acceptance for a year. You need a good reason but I think that if you present your case in a good way you can get it. The way I see it, it's one less spot they have and they will for sure get thier money because they can just pull someone off the waitlist and they will for sure get that filled with all those applicants who would kill to get into Columbia.......What's your potential reason for this? Just curious.....