I am so sorry to read this, I know your heart is breaking, as is your sons and his girlfriends, and I'm sure grandpa is upset as well. Things happen, and nothing can be done about it now. I can't believe those vets, makes me love my vet that much more, as she has told me if I ever need her anytime day or night, not to ever hesitate calling. Just be there for your son, I'm sure he's going to have some very hard days.