SPANISH FORK CANYON — Two vehicles traveling the same direction ended up in a deadly head-on collision on U.S. 6 in Spanish Fork Canyon Wednesday night after one of the vehicles spun out in front of the other, a Utah Highway Patrol official said.

One adult died at the scene and four others, including an infant, were considered to be in critical condition after a car and an SUV pulling a trailer crashed into each other midway up the winding canyon road as they traveled west in the canyon, officials said.

The scene was exacerbated when an ambulance ran into one of two medical helicopters called to the accident. An ambulance driver "clipped" one of the helicopter rotors, breaking part of it and rendering it temporarily flightless, said UHP spokesman Cameron Roden.