The parking service reported that the rockfall had occurred shortly before 18:00 in the vicinity of the stop of the shuttle in weeping, where three people were injured and several others stranded.
The rock collapsed at Cable Mountain, about an hour east of St. George in the southwestern corner of the state, plummeting about 3,000 feet and a cloud of dust and sand.
Some visitors to the Weeping Rock Trail were temporarily stranded by rockfalls, but were able to save themselves.
The rocks crashed into a vehicle near the east tunnel of the popular and mountainous Going-to-the-Sun Road, killing the teenager and injuring their parents and two other children in the car. [1