Investigation underway following house fire in southwest Fresno

FRESNO, Calif. (KFSN) -- Fire crews are investigating what caused a home to catch fire in southwest Fresno.

Crews were called out at about four this morning to Walnut Avenue near Florence, across from Edison High School.

Officials say when they arrived, the building was engulfed in flames.

The house was empty and no one was injured.

Firefighters were able to keep the flames from spreading to adjacent homes.

Authorities say the response of some fire crews was delayed due to the thick morning fog.