Fire crews are trying to find out what caused a fire Thursday morning that damaged three homes.

Fire crews responded to the scene a little after 3:30 Thursday morning, at a home in the Glen Elk area. The house was fully engulfed, and the fire somehow spread to the house next door. It also did damage to a third home.

Nobody was in any of the homes at the time of the fire. The city fire inspector has been called to the scene, and is investigating the cause.