I am trying to find out if the following describes an event in the title listed on the subject line...
The example I recall consisted of a single long-chain molecule -- that was essentially unbreakable and invisible. In the story, one of these molecules was stretched across a road in advance of a military troop transport. The vehicle and its inhabitants were sliced by the molecule. there were no outright fatalities, but due to the extreme thinness of the "string," the effects of the slicing were unpredictable.
