CNN — (CNN) -- Sheriff's deputies could try as soon as Tuesday to recover the bodies of five people who died in a rockslide near a scenic Colorado waterfall.
The lone survivor of the rockslide, 13-year-old Gracie Johnson, was taken to Children's Hospital Colorado near Denver. Her condition is unknown.
Chaffee County sheriff's deputies rescued her from the debris Monday after tons of rock careered down on a vantage point looking up on Agnes Vaille Falls in Nathrop, Colorado, sometime before 11 a.m. Monday. The site is about 120 miles southwest of Denver.
The site of the slide is still very unstable and no one is allowed in the area other than the authorities, Sheriff Pete Palmer said Monday. Engineers are evaluating the conditions and Palmer said crews will return to retrieve the bodies "as soon as the area can be declared safe for the search teams."
The names of the hikers killed by the rockslide have not been released. It was not known whether they were related.
The trail leading to the falls is a relatively easy one, according to the U.S. Forest Service, making it popular with families. However, rockslides are apparently relatively common near the trail, according to hiking website Alltrails.com.
The cause of the rockslide is not known, but Palmer said heavy rain this month in Colorado may have been a contributing factor.