Ouch, that really sucks

The ESC is "water resistant" but completely sunk, yeah, that'll kill it. Are all the other electronics dead too?
I don't think I'd be confident running over water even with a supposedly completely waterproof car (like my Traxxas 1/16 is technically supposed to be, except for the aftermarket servo I got after the original broke). Given my luck with electronics it'd die anyway!