He finish removed snow and parked. Got into a 3 pt stance & had both feet on the top step, moved his right foot front the 1st step to 2nd step his L foot slipped off the top step. tried to catch himself with his hands lost his grip & fell to ground on his right side fracture his r pelvis. 24% ft & quit snowing at time of accident. He had cleaned light snow off top deck with feet,