Investigators have been unable to determine the cause of the Marco Polo condominium complex fire, city officials announced today, more than three months after the July 14 blaze, which left four people dead and caused more than $100 million in damage.

Mayor Kirk Caldwell, along with Honolulu Fire Chief Manuel Neves and Honolulu Fire Battalion Chief Jeff Hooker, made the announcement at a news conference this afternoon at the McCully-Moiliili fire station on Date Street.

Despite what Caldwell called an “exhaustive” investigation, Neves said the official cause is “undetermined” because of “extensive damage” in Unit 2602, where the Kapiolani Boulevard high-rise blaze began.

The Honolulu Fire Department had previously identified that unit as the place of the fire’s origin, and had eliminated arson, cooking and use of a flammable liquid as factors in its cause. Neves reiterated that information today and added that investigators also eliminated a drug lab and drug paraphernalia as a cause. He said that smoking could not be eliminated as a possible cause.

The seven-alarm fire quickly spread throughout the 36-story building, killing three residents — Joann M. Kuwata, 71; Britt Reller, 54; and his 87-year-old mother, Jean Dilley — in two separate neighboring units on the 26th floor. Marilyn Van Gieson, an 81-year-old woman who was disabled and waited in her 32nd-floor condo for four hours for firefighters to rescue her, died 20 days later at Straub Medical Center.

HFD last month estimated the fire caused $107 million in damage with more than 80 of the 568 units affected, including 30 that were destroyed.

Caldwell described the 130 firefighters who responded to the fire as heroes. “I believe because they did their jobs, lives were saved,” he said today.

Marco Polo Fire Investigation by Honolulu Star-Advertiser on Scribd