A deadly rockslide at Glacier National Park is prompting a warning about potential dangers for tourists.
A family of five was driving along a popular Montana road when their car was hit by falling rocks, killing a teenage girl inside .
Pat Cummings said she was driving down the road in Glacier National Park when traffic stopped amid sounds of horror.
"I could clearly hear a woman crying frantically, screaming, you know, 'Please help her. Someone please just help her,'" Cummings said.
Park officials confirm a car driven by a family of five from Utah was caught in a rock fall that generated enough debris to fill the bed of a pickup truck.
Some of the stones were a foot in diameter.
"Whether it's rain, whether it's wind, you know, all of these things can cause rocks to fall," said Lauren Alley, a spokesperson for the park. "But rockfall in this magnitude is very unusual."
A 14-year-old girl in the car -- who park officials say was from Farr West City, Utah -- died in the incident. Her parents and two siblings were injured.
"If there had been more cars probably closer together, I do think it could have been worse," Cummings said.
The rockslide happened on the 50-mile long "Going-to-the-Sun Road," driven by about 2 million people every year.
The road's last rockfall death was more than two decades ago -- and the danger is not always preventable.
"It's a little bit tough to inspect the mountain above the road," Alley said. "Rocks are continually shedding as part of that geologic process."
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