You missing USPS psckages? Maybe here is what happened to them...

These videos show S.O.P. for package handling. I can't tell you the number of times I visited the the post office late at night to get the previous day's mail from our PO box. I usually park in the customer parking lot at the end of the loading docks. While walking to and from the car, i can literally hear packages being thrown into the trailers being loaded. It's an unmistakable sound.

Poor business practice for sure, but not uncommon.