Matt Krantz

USA TODAY

A Yellowstone National Park concession worker was killed Friday when she fell off a cliff overlooking the Grand Canyon of the Yellowstone River.

Estefania Liset Mosquera Alcivar, 21, of Quito, Ecuador was talking to co-workers near the rim of the trail at 3:15 a.m. Friday when she fell over the canyon's edge, according to a statement from Yellowstone National Park.

Coworkers at the scene called 911 and paramedics arrived. When there was enough light, a rescue team determined a human would have not have been able to survive the fall. Her body was airlifted out of the canyon at around 10 a.m.

In its statement, Yellowstone National Park reminded visitors to "use caution on the rim trails at the Grand Canyon of the Yellowstone." An investigation is ongoing.