Authorities say family members of twins from Australia are traveling to Colorado after the two women were shot in the head at a firing range.

An investigation of the shooting south of Denver was continuing Wednesday. No suicide note was found.

One sister died and the other was critically injured during the Monday incident. Since the 29-year-old women look alike, authorities haven't been able to determine yet which one is dead and which remains alive.

The women are from Victoria state in southeast Australia. Both were in the U.S. on cultural exchange visas. One sister had been due to return to Australia on Tuesday.