Lightning damage to underground cables

A case study is presented of a defect that occurred in the optical fibers of an underground optical cable resulting in the stoppage of a communication service. An investigation revealed broken optical fibers in the optical cable. This breakdown is presumed to be due to a lightning surge, from the observation of a thunderstorm and the damage at the location of the breakdown on the day of the breakdown. The cause of this breakdown was investigated and measures that can be taken to prevent a reoccurrence are reported.