My wife bought this bike over 20 years ago and put only a couple hundred miles on it, it's been sitting in our garage for about 12 years. I started to clean it up in hopes she would ride it again and noticed the rear wheel grossly out of true. Looking closer I saw two spoke nipples with the heads sheared off. My wife is about 110 lbs so it's not from her riding it.

Not sure what to make of this, I've seen broken spokes but never broken nipples.