vine dying

My grandfathers pipe vine, which was thriving a month ago is now almost completely dead. The leaves are turning black and falling off. Any ideas?
My butterflies are all going to leave, or already have.
thanks,
jackie

Could there be a critter under the plant that's creating tunnels? Try sticking a turned on hose nozzle in the ground around the base to see if there are hollow spots. Chipmunks, shrews and voles have done similar damage to various plants here in previous years. My pipevines hosted tons of swallowtails and were looking pretty ratty a few weeks ago but thanks to frequent afternoon thunderstorms they are leafed out in lots of new growth.