Michael felt unwanted.
(In fact, only William didn't care, but he doesn't know that.)
He wasn't going to do anything about it though.
Until one rainy day, he goes out in his usual nocturnal sneak out. He fell in an old well that was mostly taken back by natures.
He drown and died there.
Ending up somehow "possessing" some mud and algea.
He was able to get out the well and dragging his corpse with him.
Once at home, he rolled the body in a tarp and hide it under his bed.
But then, he discover that no one had noticed his absence. (It has been a day.)
Feeling alone, he decided to prepare to run away and start packing some of his stuff.
Some days later, he pretends to feel very exausted and tell his familly he's going to take a bath and then go to sleep.
He then put his naked corpse in the tub and lock the door behind.
He took his bag and gets out by his bedroom's window.
But Evan notice him during his escape and ask to promise he'll come back.
Michael doesn't promise anything but did say he'll "come back".
They never see each others until 93, where Evan go work for Freddy as a technitian.
And a certain technitian named Mike Shmith works there too.