The present invention relates to a method of monitoring a fluid carrying conduit, comprising interrogating an optic fiber positioned along the path of the conduit to provide distributed acoustic sensing, measuring by distributed acoustic sensing the acoustic signal at each of a plurality of discrete longitudinal sensing portions along the length of the optic fiber, to monitor the optic fiber for the presence of a first characteristic signal, the first characteristic signal being indicative of ground heave the vicinity of the optic fiber, and determining that a failure has occurred in the conduit when a first characteristic signal is measured in the distributed acoustic sensing.