the neighbour of my workplace decided to grow conifers under the power line,way before i worked there,10 years before maybe?
but one day a member of staff ran up to me saying the lines down.the tree was on fire and the the line was dancing on the floor,right next to our stables.two fire engines,and a hefty fine to the neighbour i believe
sorry about the long story but you should contact the local council for advise,they may know whom is liable for the power line