I think in a situation like this instinct and reflexes kicks in and you'd go for your son, whether you want to or not. Preservation of offspring is (or at least should be) overriding common sense and/or logical thinking. If there's a chance I could rescue him I would (probably) dive in. I wouldn't even notice all the other people.
Just hope I never get into a situation like that.
Just hope I never get into a situation like that.