A $120,000 report paid for by Hawaiian Electric Co. concluded that the local utility "could not have prevented" the Dec. 26 outage that cut off power to its 294,000 customers on O'ahu.

The report's findings, if adopted by the state Public Utilities Commission, would likely mean that the company won't have to pay for damages suffered by customers during the islandwide blackout.

In a 97-page report filed with the PUC yesterday, Power Engineers of Idaho reaffirmed HECO's earlier findings that multiple lightning strikes short-circuited a major transmission line connecting the local utility's Kahe and Waiau power plants in Leeward O'ahu.

The report also supported HECO's findings that the short-circuit caused a severe drop in voltage that resulted in the shutdown seven power generators at five different power plants nearly simultaneously.

"HECO could not have reasonably anticipated or prevented the damaging effects and instability caused by the lightning," Power Engineer said.

"The system operated appropriately under the circumstances."

State Consumer Advocate Catherine Awakuni said her office is reviewing the report and is conducting its own investigation into the outage. She said she is in process of finalizing a consulting contract with Sega Inc. of Kansas to help conduct the state's study.

The Dec. 26 outage, which lasted more than 12 hours, disrupted traffic throughout O'ahu and caused retailers to shut down early during one of the busiest shopping days of the year.

The outage drew international attention in part because President-elect Barack Obama and his family were vacationing on the island at the time, and their beachfront home was left without power.

About 700 HECO customers have filed outage-related claims ranging from spoiled food to damaged to appliances and other electronic equipment,

Company spokeman Darren Pai said.