These types of swimming pool injuries and deaths should never occur, especially in a school swimming pool with a lifeguard. Proper supervision was required and it was necessary to come to the student's aide before he drowned. Lifeguards are trained to constantly scan the water for swimmers in peril, especially because most drowning victims do not splash or make noise. I am not sure about the specifics in this instance, but quite often there are not enough lifeguards for the number of swimmers and they are not properly positioned on the deck to observe the pool.
The family of the decedent has legal rights and can consider filing a Michigan Wrongful Death Lawsuit. The ultimate success of the case will be determined by the specific facts and the accounts of witnesses at the pool. It is important that the family choose an experienced swimming poool accident and injury lawyer for their case because these matters are highly specialized and require a lawyer with that specific expertise.