What Caused Gary Coleman's Tragic Fall?

Gary Coleman underwent dialysis sessions three times a week to treat his congenital kidney disease and shortly after he slipped and hit his head leaving him with a one-inch gash.
His friend Jeremy Spence explained that Gary drove himself to the hospital and says:

“Dialysis had taken a lot out of him that day. He just wanted to go home, but he was pretty weak. He had no strength at all.”
The fall caused intracranial bleeding and he slipped into a coma before being taken off of life support.
Sad, sad.
[Image via WENN.]