in the hounds of baskerville,what had actually happened to hugo baskerville?was there any supernatural element in the story?

Hugo Baskerville's death was caused what his friends remember to be a great black beast,shaped like a hound but larger than any mortal hound. It was mutilated the body of the man and frightened the other men so much that they psychologically deranged for the rest of their lives. It is possible that the gigantic proportions of the hound as conveyed by the friends could have been an exaggeration due to their being inebriated. The hound could have been any other moor hound which was thirsty for game but due to the high levels of alcohol in their blood,it seemed monstrous to them. The legend continued because many members of the family died sudden,bloody and mysterious deaths after that and it became part of local lore thus,furthering these stories of the supernatural beast. It could very well have been any crazed dog like the one Stapleton used and whose work was eased by the fear already there thanks to the legend.