Has lettermail mail in small bubble mailers from Canada to USA delivered ground mail service ever been lost?

I'm talking about letters with the senders and addressee's addresses.Has lettermail mail in small bubble mailers from Canada to USA delivered ground mail service ever been lost?
Yes, one was lost in 1989 when a train traveling between Calgary and Ogden, Utah, had the cargo door of the mail car come open in a freak tornado accident. A single, bubble-enveloped letter slipped out the door and was lost in the Great Salt Lake. Fortunately, thanks to the bubble wrap, it floated, and was recovered by a pair of Norwegian scuba divers a couple months later. The letter was sent by one Minnie Pendergast to her nephew, Robert Wondergem.



Other letters have been lost over time, but this is the only known time one on letterhead, wrapped in a small bubble mailer, was lost between Canada and US traveling on the ground.



As for delivery time, no one can tell you "exactly," but I'd start to worry after a week.



Added later:

PLEASE stop emailing me rude and abusive notes. If you do not want to believe that I know what I am talking about, that is fine, but please have some manners. You are just being obnoxious.



Added even later:

Apology accepted. Peace.
Of course mail can become lost. The postal services move billions of pieces of mail yearly. Even minute loss ratio would mean thousands of lost articles.



Letter mail takes about a week to go from Canada to the US, but it could take longer occasionally. It does have to pass US customs, for instance, and that can slow it greatly if it is opened for inspection.Has lettermail mail in small bubble mailers from Canada to USA delivered ground mail service ever been lost?
I can't cite a specific instance, but I have seen enough stories about VERY old mail being found various places to be certain that it HAS happened more than once. If it was mailed more than 2 weeks ago, and has not been delivered, something is probably wrong.
Somehow mine was lost







vHas lettermail mail in small bubble mailers from Canada to USA delivered ground mail service ever been lost?
Many times and will be lost many times more