On Friday, February 26, 2021 at 10:30:02 PM UTC-5, AK wrote:
Today while riding, my rear brakes locked up.

While investigating, the rear tire blew up causing part of the rim on one side to split off.

The tech at the shop said the brakes had worn through the rim.

Seems hard to believe that hard rubber can wear thru aluminum.

Is that common ?

It's been known to happen. I had a rear wheel that showed signs of cracking along the bead due to wear. It isn't something that happens in a short period, it takes years usually of wear, unless you ride every day in wet muddy conditions.