BLACKSTONE, Mass. (WPRI) — Rescue crews were called to the rear of a Main Street address Sunday in Blackstone after a man was discovered at the bottom of a small, rocky cliff in the woods.

According to the Blackstone Fire Department, 911 dispatchers got a call from a woman at 5:17 p.m. who’d been walking in the woods and saw a man on the ground unconscious.

Rescuers found the man had tumbled down into a hollow, hitting multiple large rocks. It took a complex process for rescuers just to get to him, then to stabilize him and haul him up and out of the hollow.

The man had serious head and leg injuries, and an ambulance crew rushed him to the University of Massachusetts hospital in Worcester for treatment.

Fire officials didn’t identify the man.