LONDON, ONT. -- The province's Special Investigations Unit will not invoke its mandate following a weekend incident in Hanover.

Shortly after 4 p.m. Sunday, police were notified of a mental health patient who walked away from the Hanover and District Hospital while under-dressed for the weather.

Officers located the 33-year-old man on top of a greenhouse roof at the former John Diefenbaker Secondary School.

While attempting to convince the man to come down, he fell through the glass roof and onto the floor.

He suffered a fracture to his shoulder and minor cuts to his hands.

Police say they won't lay any charges.

The SIU is an arm's length agency that investigates events involving the police that have resulted in death, serious injury, or reports of sexual assault.