BOSTON -- A 9-year-old Uxbridge girl was hit in the head with a high-velocity projectile while walking with her father at Lookout Rock on Saturday.

Madison Bruneau's eye socket was shattered, bone fragments lodged in her brain and her retinal nerve nearly shattered.

VIDEO: Mystery Object Shatters Girl's Eye Socket

It happened on a hike Saturday afternoon at Lookout Rock not far from her Uxbridge home. The 9-year-old was goofing around on a trail when something went horribly wrong.

"She was making howling sounds, and so was someone else in the distance. The next thing she was clutching her head, holding her head. Her dad looked and saw her bleeding. He called 911," family friend Julie Daoust said.

Madison was ultimately flown to Children's Hospital for three hours of reconstructive surgery. Police are trying to figure out how the incident happened.

"We're thinking that it may have been some sort of a slingshot, but we're not 100 percent sure," Northbridge Police Department Officer Tom DeJordy said.

"Whether they meant to hit her with a rock or whatever object it was, it had to have been high velocity to do the damage it did," Daoust said.

Police have searched the trails, but officials said it's hard to find clues in the vast area. Now, they're looking for the public's help.

"If anyone saw something suspicious or anything that would help us in our investigation, we would greatly appreciate the help," DeJordy said.

"I just want someone to come forward, just to find out who did this. It's just awful seeing her like that," Daoust said.

Anyone with information is urged to call police at 508-234-6211.