Fire investigators determined today an Aiea house fire that killed a 65-year-old woman and caused $400,000 in damages last week was intentionally set.

Police said they suspect no foul play and are not looking for any suspects.

The fire at 99-518 Ulune St. appears to have started in an enclosed patio in the back of the house about 10:20 p.m. Friday, said Honolulu Fire Department Capt. Terry Seelig.

Police said a 65-year-old woman died in the fire; neighbors identified the resident as Jane Ebisui.

The Honolulu Medical Examiner’s Office deferred a cause of death and hasn’t confirmed the woman’s identity, pending a check of dental records.

Seelig said fire investigators used burn patterns, evidence at the scene, and witness statements about the fire’s origin to determine how the fire started.

On Friday, firefighters responding to a call about 10:20 p.m. found the home engulfed in flames and were told there might be people still inside, Seelig said.

After controlling the fire, firefighters entered the single-story structure and found the body of a woman in the enclosed patio. No one else was injured.

It was the fourth fatal fire on Oahu this year.