An investigation of the assault is underway by police. There needs to be another investigation: of the school's immediate response in suspending a student who assaulted another for only two days.
If I was the father of that this kid in a coma, I already would have attorneys lined up to begin lawsuits, not for monetary gain but for punishment. I would sue the parents of the kid responsible because in most instances of bullying, parents are to be held responsible; and I would sue the district for keeping the bully at school if it was known he was a bully.
Last thing, I would seriously consider engaging an individual to find the kid who put my son in a coma, to beat the living shit out of him - an eye for an eye. That's extreme, but it comes from my childhood when my brother and I were bullied by an older kid who lived down the block and made life absolutely miserable for us for three years. I can tell you in all honesty that had I access to a gun at that time, I would have shot that kid with absolutely no hesitation. Years later after I had grown up, I went looking for the four people who bullied me most as a kid and over time, I found them all and got my revenge - except for the one kid above who bullied me the most. He got down on his knees crying when I finally ran across him in a bar and dragged his sorry ass outside, and I found him too pathetic to bother with. When I finally got the last of them, I felt vindicated; it was a weight removed that I had carried for a long time.