An electrical fire caused “major” damage to a four-plex apartment building on Skysail Avenue early Wednesday, fire officials said.

The fire began around 5:50 a.m. in a downstairs apartment in the 8200 block of Skysail Avenue, the St. George Fire Department said. When firefighters arrived at the scene, they found fire in two apartments and the building’s attic.

Three of the four units were occupied by 12 adults and three children, SGFD said. All residents self-evacuated, and there were no reported injuries.

The fire was under control at 6:23 a.m. The building and contents inside suffered “major fire damage,” SGFD said. The downstairs apartment, where the fire originated, was “gutted.”

Fire investigators determined that the fire was of electrical origin.

Red Cross was called to assist residents displaced by the fire.