B.C. Transmission Corp. staff are continuing to pore over computer data logs, which record data in milliseconds, corporation spokesman Mike Witherly said yesterday.

“It’s quite a sophisticated computerized system that monitors the power throughout the province,” he said. “They are going to be looking for the tiniest little changes to try to get to the bottom of exactly what happened.”

He could not say how long it would take to pinpoint the cause.

A circuit imbalance in the transmission system delivering power to other lines tripped the protection and control system, shutting off power to homes from Ladysmith to Victoria about 5:45 p.m. All lines were back in service by 8 p.m. that night.

The power outage trapped some people in elevators and took place as thousands of families were preparing Thanksgiving meals.