I reluctantly post this as so much has been already said, some of which I fully agree with and some I question.

My opinion.... Akita's are known to be dog aggressive and many Akita owners will tell you it takes a special kind of owner to handle this dog. That being said.... I do not lump all dogs into one category. I make my judgements on individual merit. In this case, I'm not sure how the man falling off the roof would cause the Akita to react to severely bite the man (especially the dogs owner). Perhaps it was so startled it lost control. None of us will know since we were not there to witness this unfortunate incident.

Liz hit the nail on the head when she said the owners should know the temperament of their dog. If they don't then shame on them. If they have even the slightest inclination the dog is not safe around the children, the dog should be rehomed.

If the dog came from a reputable breeder, this would be an excellent source of information on the dogs relatives temperments. There are also many articles online about AKita's. If the breeder is of no help, contact someone from the National Akita club and they will be more than happy to help you. I'm sure they would be more than willing to offer help in this area. If nothing else, they can point you to Akita rescue if rehoming the dog does come into play.