City fire investigators say they still don’t know what caused a three-alarm fire that spread through an Ewa Beach townhouse apartment complex nearly two weeks ago.

However, the Hono­lulu Fire Department’s investigation into the June 6 blaze, at 91-613 Kuilioloa Place, traced its origin to the patio area of a ground-floor unit, department spokes­man David Jen­kins said Tuesday. The fire, which had displaced 19 people, caused an estimated $750,000 in total damage to two buildings and their contents, Jenkins said.

HFD also gave the results from investigations into three other recent fires on Oahu:

» A Friday fire that spread through the caretakers quarters at Leeward Cemetery was caused by accident when someone lit a cigarette near gasoline used for yard equipment that had spilled, Jenkins said. The blaze caused an estimated $60,000 in damage.

» A Saturday fire at the Century Center condominium complex was caused by accident when a stove was left on overnight, igniting the cabinetry above it, Jenkins said. The blaze caused an estimated $40,000 in damage.

» A Sunday fire that destroyed a home on Kawai­puna Street in Hau­ula was caused by accident when an electrical blaze sparked in the garage, causing an estimated $400,000 in damage.