The Austrian Federal Railways (OEBB) rail-network operate several trans-European connections, thereof approximately 20% are exposed to natural hazards. For trains, obstacles in the tracks, damage to the track bed and direct train hits are the most relevant hazard scenarios. Classical permanent protections structures are sometimes hard to realize due to technical reasons and the limited time windows available for construction work. Therefore detection technologies gain more importance as an alternative to classical protection measures. Distributed acoustic sensing (DAS) with fiber optic cables is in use worldwide for monitoring pipelines or e.g. securing industrial and military facilities. This study evaluates if reliable detection of hazardous processes in the track area is possible by using existing fiber optic communication cables. We show that processes such as rock fall or tree-throws can be detected well, but due to the high sensitivity of the monitoring system, interfering signals still produce a relative high number of false alarms.