An investigation into the death of an O'ahu Transit Services mechanic has determined that the company's safety procedures were not followed, OTS said yesterday. An earlier company statement said proper procedures had been followed.

In a statement released yesterday, the company said "it was discovered that the mechanics conducting the repair had not chocked the bus as the company previously reported."

A bus is considered chocked if its tires are blocked to prevent it from rolling.

The company said the mistake did not cause the accident and that the cause is still under investigation.

"The accident occurred after the repairs to the bus were completed and while the mechanics were preparing to return to the storage yard. At that point the tires would not normally have been chocked," Michelle Kennedy, manager of customer communications for OTS, said in a news release.

As a result of the accident, OTS maintenance department officials have been conducting classes to reinforce safety rules.

A 59-year-old mechanic was killed Monday afternoon when the bus he was repairing in the Moanalua area rolled over him.

Alan T. Ishimaru, of Kuli'ou'ou, was working on the bus, which had been taken out of service because of a mechanical problem. The accident occurred near the intersection of Ala Mahamoe and Jarrett White Road, which leads to Tripler Army Medical Center.

The bus rolled backward while it was parked on a hill, fatally crushing Ishimaru and traveling through the intersection before smashing into a rock wall and stopping in front of a house.

Honolulu police are investigating the incident as a traffic fatality and have not opened a criminal investigation, police said.

To open a criminal investigation, someone would have to have been driving the bus, police said.

Reach Peter Boylan at pboylan@honoluluadvertiser.com.