The commercial real estate market has no reason to collapse. In these cities with a lot of vacant office space, like NYC today, what do you also have? Enormous demand for apartment housing. Land owners never lose money in these hot markets where apartments are leased the day they are put to market. Your building could burn down and it doesn't matter, the money is in the deed to the dirt and the zip code, and the potential rents that this piece of dirt in this zip code can yield based on the zoning of the property.