https://techcrunch.com/2019/08/30/did-your-aluminum-apple-watch-mysteriously-crack-itself-apple-might-replace-the-screen-for-free/

So your aluminum Series 2 or Series 3 Apple Watch is suddenly cracking around the edges… but you don’t remember bumping it on anything, or being particularly rough with it.

Surprise! It might not be your fault at all.