A small power outage in Langley that left 10 Puget Sound Energy customers without electricity for nine hours late Wednesday was caused by an equipment failure on an underground cable, a PSE official said Thursday.

The outage occurred at 2:30 p.m. Oct. 19.

PSE spokeswoman Allison Stanford said restoration took longer than repairing a downed overhead line because a work crew had to access the underground cable, and then make repairs and replace equipment.

Final repairs were made by 11:30 p.m., and power was restored by 11:45 p.m., Stanford said.