10 mth. pup Golden/Pyrenees destroys EVERYTHING in backyard if left alone while we are at work, What can I do?

We are at our wit's end, perfect dog if not left alone. We have to work/school and he has ruined hot tub cover, broke fences, ate patio furniture, pretty much anything in his sight he destroys. Usually within the 1st hour of being left alone. Don't know what to do and can't bare giving him up. PLEASE HELP!