If memory serves that particular brown in recent manufacturing from Lego was known by the public over some time to have embrittlement issues, so probably not something you did to it, but something as of now that Lego has fixed on their end if you pick up that brown from a current set or from their stores.
Yup. And afaik Lego will replace the broken pieces for free.
they will? is there a form to fill out or something?
You can submit a request on their website apparently
The old brown from the 90s had the same problem; I’ve broken several while dismantling old used LEGO and it sucks. A lot of them were used in the old, kickass Pirate ships.
I have the complete shell of that pirate ship and the body is still very strong. All the brown accessories however (muskets, barrels, etc) turned to dust long ago.
Where is your God now!?
Box of shame or hall of Fame, you decide where to hang this bricks frame