A cable fault occurred on a HV subsea power cable in Europe, at an unknown location. For large power cable assets such as subsea cables, windfarm export cables or HV onshore transmission cables, finding cable faults rapidly is crucial to minimizing downtimes caused by these faults. Fiber optic Distributed Acoustic Sensing (DAS) is a key enabler for this task, as it pinpoints the. This article introduces case studies of failures that have occurred in optical fiber cables as well as some countermeasures against such failures. It also includes a list of common fault location items.