Police spokesman Steve Martos says a 16-year-old and a 12-year-old were riding the ATVs near 36th Avenue and Minnezona Avenue on Saturday night.
Martos says the girls were trying to take a photo while riding and ended up hitting a parked vehicle.
He says both were taken to a hospital and one of them is listed in extremely critical condition.
No further details were released.
- Dignity Health World Class People. World Class Company. Excellent care, delivered with compassion, for all in need.
- Eyes on Education A view of Arizona's education system from all angles.