Justice officials say an incident at the Whitehorse Correctional Centre Wednesday evening never threatened the public.
About 20 RCMP officers were called to the jail to set up a perimeter at about 6:30 p.m.
Justice communications analyst Shari-Lynn MacLellan says the incident began around 5 p.m. with an inmate in the isolation unit.
"During his allocated exercise time, the inmate managed to remove a phone from the wall. He used the phone to do damage to the segregation unit and was able to access an electrical and plumbing shaft and make his way into the ceiling of the unit," she said.
"After a period of time, the correctional staff were able to talk the inmate into coming out of the ceiling and he was peacefully escorted to his cell."
The incident is being reviewed, and MacLellan can't say what actions will be taken.
She says the whole thing was over by 8 p.m.