NAPAKIAK, Alaska (AP) – An early morning fire at an Alaska jail killed two inmates and seriously injured a guard who was trying to release them.

The Anchorage Daily News reports that authorities have not yet identified the victims of the fire in the village of Napakiak in southwest Alaska.

Alaska State Troopers received a report around 1:30 a.m. Sunday that the jailhouse was “full engulfed in flames” and that two prisoners inside their cells “were not able to get free” of their cells.

The injured guard was flown out of the community by a medivac helicopter. Two other guards escaped the building without reported injuries.

Police say it was not immediately clear how the fire started, although a guard reported the blaze was the result of a prisoner setting fire to a mattress.

Information from: Anchorage Daily News,