Without looking at the board there is really no way to tell - if the water shorted one circuit together it might be OK, or if it fell onto the microchip it may have killed it.
I would let it "dry out" for a few days, maybe even put it in front of a heater vent or a fan to speed it up. Then you could try reconnecting it and see what results. If it is still dead, the only thing I can suggest would be to send it in to us. See this page if you need repairs:http://www.deckkeyboards.com/returns.php