Updated

A 13-year-old girl who was the only survivor of a Colorado rock slide that killed her entire family told authorities her father shielded her as boulders crashed down on them and likely saved her life.

Rescuers dug Gracie Johnson out of the rubble after Monday's slide, and she was airlifted to a Denver-area hospital with a broken leg, the Chaffee County Sheriff's Department said Tuesday.

"She told me at the last second when the boulders were coming down on top of them that he covered her up and protected her, which I believe it saved her life," said sheriff's Deputy Nick Tolsma.

Gracie's parents, Dwayne and Dawna Johnson, and her 18-year-old sister, Kiowa-Rain Johnson were killed, as were her 10-year-old Baigen Walker and 22-year-old Paris Walkup, of Missouri.

Dwayne and Dawna Johnson were coaches in Buena Vista schools, were well known in the town and very active in community events, the sheriff's department said.

"Any sudden loss of life is difficult to handle within small communities but something of this magnitude is devastating to all of us," Sheriff Pete Palmer said. "The community will come together to grieve for the friends we have lost and support the family during this difficult time."

Monday's slide sent 100-ton boulders onto a popular viewing area that overlooks Agnes Vaille falls below 14,197-foot Mount Princeton in south-central Colorado.

The massive slide left a gash the size of a football field in the mountainside, Undersheriff John Spezze said.

What triggered it wasn't immediately known, though Spezze said the area had heavy summer rain and a recent snowfall.

Rain or melting snow can make slides more likely by weakening a steep slope and making the rocks and soil heavier, said Jerry Higgins, an associate professor of geological engineering at the Colorado School of Mines in Golden.

With enough data, geologists can identify slopes that are susceptible to slides, Higgins said, but finding all of them would be a massive undertaking.

"In Colorado, there's a lot of steep slopes, and I don't think anybody's got the money to pay for the studies for all the steep slopes," he said.

Witnesses said some of the boulders were the size of cars. A hiker who heard the slide in Chalk Creek Canyon ran down the trail and called for help, Spezze said.

Tolsma said he was one of the first at the scene and heard screaming from beneath the rubble. He saw Gracie Johnson's hand sticking up through the rocks.

"I started digging her out until I had more help come and we got her all the way out," he said.

A search team was working Tuesday to recover the bodies. Four could probably be recovered using hand tools, but special equipment was needed to dislodge a huge boulder -- possibly a heavy inflatable bag -- and retrieve the fifth body, said David Noltensmeyer of the North End Search and Rescue team.

The U.S. Forest Service maintains the busy trail near St. Elmo ghost town. Spezze said officials have asked the Forest Service to close it permanently.

The trail is one of the first hikes recommended to people new to the area and is popular with tourists, said Margaret Dean, a regular hiker who has walked the trail with her 7-year-old grandson.

Dean, a copy assistant at The Mountain Mail newspaper in Salida, said the trail provides a view of the falls and the Chalk Creek Valley in the towering Collegiate Peaks.

The Associated Press contributed to this report