Very sad. I always carry a sharp folding knife... Not saying someone with a knife would have saved her, but it would have been worth a try...
Probably illegal!
I did just that on the DC metro escalator when a woman got the hem of her coat snagged in the combs. She was directly in front of me. It was eating her coat, dragging her down, and she didn’t have the presence of mind to just drop her arms and let the coat be taken off of her. She was flat on her back and slowly being squeezed as I flicked open my Spyderco Delica, and sliced the hem of her coat free of the combs with no effort, and just kept walking, as the crowd helped her to her feet. Nobody saw a thing.