I feel a lot of sympathy towards you in what you've been through.
When I visited the mother of one of the deceased (aged 19) I witnessed her devastastion. I will never forget the state she was in and felt I owed the world for being alive. I am still very close to a friend, now living in Sydney, who was another survivor in the accident. I do believe it changed our lives significantly. We now have an everlasting bond.
Be thankful that you have your sons. They will continue to question why they survived, but they are alive. It was the result of a moment of indescretion which could happen to anybody. They are alive for a reason - time will reveal.
