Wow, that's a tough one. You, your dad, family, and this man's family all have our deepest sympathy and are in our prayers.

Similar incident near here a few years ago, farmer vaccing out his own bin of beans. His family, more specifically his daughter-in-law, became very active in educating and informing fire dept rescue squads and any other groups that might become involved in a potential rescue. I think this has helped them deal with the pain in a constructive manner and help others out too.