City officials must be relieved that no one was hurt when a makeshift addition to a house in Kalihi collapsed Sunday, scattering pipes, tarps and plywood down a hillside and into a stream.

Had there been injuries, they would have faced harder questions about why the jury-rigged, illegal structure had been allowed to remain in place after years of complaints from numerous sources - most notably, the Honolulu Fire Department.

Mayor Mufi Hannemann should investigate the incident and get some answers from his subordinates, including officials of the Department of Planning and Permitting and the Corporation Counsel, to see whether corrective measures could have been taken sooner and, if so, why they weren't.

The mayor should consider referring the matter to the city prosecutor for possible criminal action because the property owners did not respond to citations and fines for construction code violations. Otherwise, the city sends a signal to other scofflaws that they can violate building code requirements without facing consequences.

More than 50 people, including at least one child, were housed in the maze of cobbled-together rooms, paying between $200 to $850 a month in rent. Residents reportedly lived in unsanitary conditions with access to only two bathrooms, leading them to urinate outdoors and in the stream.

The city has known about the house for at least three years, having issued a notice of violation in March 2005. In October 2006, more than 18 months later, the city sent another notice, levying fines when the property's owners did not correct the violations.

The fire department, concerned about “;unsafe conditions,”; sent a letter to the city in March 2007 asking officials to “;expedite legal actions.”;

It appears officials are moving ahead to clean up the property. Planning Department Director Henry Eng said earlier this week that city attorneys are evaluating options “;to ensure public health and safety.”;

The city's actions are better late than never. Although there are procedures officials must follow, concern for health and safety should have prompted them to move more quickly. Further, with possible contamination of the stream, state health officials also should have conducted an investigation.

Code violations aren't usually as hazardous as the Kalihi one and city regulations are geared toward having property owners comply with provisions rather than punishing violations. Accordingly, the department's director is given latitude in enforcement.

However, the City Council should review the procedures so that compliance and enforcement are more tightly structured.