Originally Posted by oneofthosepeopleyouloveto hate

I see a couple possibilities here.

First, how do you know the TSA lock wasn't opened? Is it a lock that shows whether it's been tampered with? If it is, and the bag wasn't unlocked, I'd guess the TSA officer had to inspect your bag, and either 1) didn't have, 2) couldn't find, or 3) was too lazy to fetch the TSA master keys, and opened your bag by breaching the zipper. It's a simple procedure easily done with a pointed object. Unfortunately, it may wreck the zipper!

Another possibility is that the TSO unlocked your bag with a key, but the zipper broke when he/she opened or (more likely) closed it. I've had this happen before ... usually the bag was seriously overstuffed!

I tend to suspect the zipper problem was NOT the reason your bags didn't make their flight (if it was, I'd expect the broken-zipper bag would have arrived late, while the other would have been on time).