I'm not sure something like this would happen to the Shangri-La site in Vancouver, partly because that site's not that close to Coal Harbour or any other body of water. I don't even know if the bottom of the construction site was much below sea level, unless they had to put in deep pilings lest the tower sinks due to its weight, or what the soil and rock makeup is really like under downtown Van. Besides, I think that tower's already long since started going up above ground (how many floors is up to by now?)
The Fairmont Pacific Rim site is right by Coal Harbour, or at least very close to it, which I noticed as I passed by that site while in Vancouver near the end of April. That would explain why it got flooded like jlousa said.
The look on the developer's face as soon as he finds what happened to that site in Dubai? It'd be
priceless!