The incident happened at an Ottawa Area Intermediate School District building on 96th Avenue.
The janitor was on the roof looking into a heating problem. Ottawa County Sheriff’s deputies said he didn't see the skylight because of the snow-covered roof and fell through it and down 15 feet to ground.
A district spokesperson said the 56-year-old man landed on a covered cement walkway outside. School nurses brought blankets to keep the man covered while an ambulance was on the way.
The man was working at Ottawa Area Center, a school for students with special learning challenges.