The Wichita Fire Department was called to a home in the 1900 block of North Arkansas just after 6 a.m. Wednesday.
When crews arrived, they said flames were seen from the front of the two-story house.
Scanner traffic indicated the family had escaped and were in the backyard when firefighters arrived.
North Arkansas is near 18th and Waco.
The Red Cross was called for four adults and two children.
Investigators determined the fire ignited on the south end of the covered front porch, Fire Marshal Stuart Bevis said Wednesday afternoon in an e-mail response to questions. An electrical malfunction occurred in the area of a deep freezer and refrigerator.
“There were several devices plugged into an extension cord,” Bevis said.
Damage was estimated at $90,000.