Three hikers fell and two of them were killed.
The vault sits at the edge of a steeply sloped sandstone bowl, and the authorities said the three men fell into the bowl around 7:30 am on Friday.
The victims were a 65-year-old man and a 60-year-old woman, according to the press release.
The survivor was a 30-year-old man. He was taken to the hospital by helicopter.
Forest Chief Scott Brown told KSL-TV that the cause of the fall was not known, although the trail was wet and slippery at the time.
The Rangers temporarily shut down Delicate Arch Trail after the incident, but reopened later that evening, the Washington Post reported. Park officials said in a tweet that winter conditions have made the hikes slippery and advised visitors to proceed with caution.
Depending on the park service, the trail to see Delicate Arch up close and down is 3 miles (round trip) and up to 480 feet (480 feet).
At the end of the trail, hikers follow a narrow rock exposed to the heights.
