A 20-year-old college student hiking in the Colorado Rockies died on Thursday from altitude sickness.

Collegeville resident Susanna DeForest was hiking towards Colorado's Conundrum Hot Springs when she began experiencing shortness of breath and vomited on the trailhead, the Times Herald reported.

Seeing that DeForest was not up to continuing, the group of four set up camp for the night. Two of the group went for help, while a third remained with DeForest. Since there is no cell phone service in the area, the two had to hike all the way down, reaching their destination at nearly 11:00p.m.

A rescue helicopter sent was unable to land in the dark near DeForest. By the time authorities arrived at 3:30a.m. on Friday, it was too late.

DeForest was studying at Pennsylvania's College of Art and Design. She and her friends had prepared for the hike and packed properly. She had no known medical conditions.

“Her friends who were with her did all they could to get help to her in time,” DeForest's mother Kate said. “We have made a trip to Colorado to see her one last time and visit a place she loved here.”

The Conundrum Creek Trailhead spans 8.5 miles, begins at an altitude of 8,765 feet, and reaches an altitude of 11,000 feet.