The most frightening case I read about was a Lynx flying over a Norwegian fjord. It caught a cable at about 450 ft above the water level, between the fuselage and the skids. The aircraft nosed over and swung inverted on the cable. It remained swinging there for some time, before falling off. They survived intact!
Having said that, an RAF colleague of mine died during an Australian exchange tour when his Chinook hit high HT cables and went down.