SPANISH FORK — Troopers said thawing ice may have triggered falling rocks over the weekend that injured two motorists, one rock smashing into a man's face, breaking his jaw.

Emergency crews were dispatched to U.S. 6 up Spanish Fork Canyon near mile marker 178 about 2 p.m. Saturday in an area known as "the narrows" to help two injured motorists. Witnesses reported seeing rocks falling off the cliffs, some the size of basketballs.

Utah Highway Patrol trooper Steve Winward said one rock smashed through the windshield of a car, striking a 48-year-old Highland man in the face and chest. Winward said the impact broke the man's jaw, and it looked like his jaw would have to be wired shut to heal.

Another rock smashed through a second car, striking a 56-year-old Payson man in the chest, causing some minor injuries. Both men were transported to Mountain View Hospital for medical treatment.