Unfortunate.
And a reminder of the tension forces that develop on "horizontal" ropes and cables when loaded. There have been several previous incidents like this. Two I can recall:
>About ten years ago an upstate NY man was setting up a zip line in his yard. He attached the uphill end of the zip line to a large dead tree. When he loaded the line, the tree fell and killed him.
>Maybe a year ago (cannot remember where) two teenage girls were killed when a hammock rigged between brick columns in their yard pulled down the columns onto the girls.
This particular type of event happens often enough that it is worth keeping in mind when doing any kind of rigging.