The Bellingham Herald has a much nicer write up and there is a remembernce here
https://www.mountaineers.org/blog/remembering-mountaineer-sue-bennett
To think it was simply rapping off the end of the rope is an oversimplification.
She was rappelling past the boulder move a boulder move on the descent, lost her footing and took a pendulum fall near the bottom of the rappel. She hit a rock face and lost control. The accident serves as an important reminder to always close the system, somehow.
It's a terrible tragedy for the Bellingham climbing community, which Sue contributed to immensely. Sue was an amazing person, tough as they come, and an inspiring climber. She will be dearly missed by so many people.
Be safe out there.
