The subject matter of the invention disclosed herein is a hydro-demolition device and a top-down method for deconstructing structural surfaces. The device includes a rigid support frame mounted above a work-face on the structural surface being deconstructed. The rigid frame supports a cutting nozzles that move up and down along the structural surface. The nozzles may be mounted on a carriage that is movably connected to the rigid frame. The carriage may swing about a swing axis so that the nozzles move axially toward and away from the carriage. The nozzles may be movable toward and away from the work-face. The various movements of the nozzles are effectuated by rotators and drivers.