Transpower's waiting to hear how an inexperienced crew was tasked with a major maintenance job

Power was cut off to nearly 100-thousand people in Northland - when a pylon toppled after maintenance crews unbolted three legs - at once.

Transpower's completed its investigation - finding the Omexom team leader was distracted sandblasting, and inexperienced workers removed the bolts - unsupervised.

Grid Delivery Manager Mark Ryall says they're waiting for answers in Omexom's report.

He says they want to understand how a less competent crew did the job without proper supervision.

Omexom acknowledges the investigation and will complete its own mid this month.