Memorial Sloan Kettering Cancer Center, one of the premier cancer treatment hospitals in the world, had a problem. A recent analysis of patient volumes showed that it would run out of space for new construction at its Upper East Side campus in Manhattan in just a few years. It did own a site at East 61st Street and York Avenue, near the East River and seven blocks from its main campus at 1275 York. But the parcel was only 100 by 115 feet. On top of that, it was also within a floodplain.