FLAGSTAFF - Seven people are dead and another three are critically injured after two medical helicopters crashed in Flagstaff.

Preliminary reports indicate the helicopters collided near Flagstaff Medical Center. According to an FAA spokesperson, the helicopters collided in mid-air.

The crash took place just before 4 p.m. on Sunday. It is still unclear what caused the collision.

3TV has a crew on the scene and further information will be provided as it becomes available.