Plumbing Questions? Ask a Plumbing Expert.
It sounds like you have frozen pipes. You need to do whatever you can to get some heat in the area where the water heater is. The pipes probably froze when you lost power. If the heat tape is still working it might that the pipes out eventually. Or you could call a plumber with a pipe thawing machine. If the pipes are still frozen when you go to bed turn off the water at the water main so you won't have a flood if the pipes break and subsequently thaw out. The same applies when you leave for work tomorrow if nothing has changed. In the mean time leave a faucet open in case the pipes do thaw