Twin sisters from Australia have been shot in the head at a firing range in Colorado, leaving one dead and the other critically injured, police say.
The 29-year-old women have not been named and investigators say they are unclear who fired the gun, or guns, or if the same bullet hit both sisters.
The incident happened at the Family Shooting Center in Cherry Creek State Park, south-east of Denver.
The centre's owner said it appeared the women were hit almost simultaneously.
"The ladies hit the pavement virtually at the same time," the Denver Post quoted Doug Hamilton as saying.
He said that a surveillance camera caught the women falling to the ground, but not the shooting itself.
It is understood the sisters had been using small-calibre guns and had arrived at the range by taxi.
Capt Louie Perea, of Arapahoe County Sheriff's office, said the surviving sister had undergone surgery but it was not clear whether she would recover enough to be able to give an account of what happened.
Investigators are working with US immigration officials to determine how long the sisters had been in the US.