UPDATE: Fire officials say the preliminary investigation shows a high probability the fire was caused by an electrical failure from an extension cord connected to an air conditioning unit inside the home.

SBFD reminds the public air conditioning units should always be plugged directly into a rated wall outlet and never use an extension cord or power strip.

ORIGINAL STORY: SOUTH BEND, Ind. -- The South Bend Fire Department reports crews responded to the 1400 block of Lincolnway East for a reported structure fire with people trapped inside just after 11 p.m. Wednesday.

Units from the Mishawaka Fire Department were returning from Memorial Hospital and already in the area. Mishawaka crews soon arrived to assist.

Crews on scene immediately began searching for victims.

Four adults and an infant were safely rescued from the multi-family home and evaluated on scene.

Fire officials say the fire was under control within 15 minutes and contained to one room.

No injuries have been reported.

The home sustained significant water and smoke damage throughout.

The cause of the fire remains under investigation.

NIPSCO and the Red Cross responded to assist residents.