Four people fell off the Ramcharger chairlift at Big Sky Resort on Saturday, Feb. 11.

The group included a ski instructor and three children in a lesson, said Chad Jones, a spokesman for the resort. They were transported immediately to Bozeman Deaconess Hospital, and have all been released.

“We’re still really not sure what happened,” Jones said. “But it does appear that one or several of the children did not get fully seated. They fell less than 20 feet.”

An investigation has shown that the accident was not caused by anything mechanical, Jones said.

“Guest safety is our number one concern and priority. We think all accidents are preventable, and we really want to evaluate how we can manage this process and improve in the future,” Jones added.