It is popular to blame the employer for every mishap experienced by a worker. But at the end of the day coming home with all the parts you left with or even coming home at all is a personal responsibility.
No one is responsible for you except you. I have had some wonderful employers who cared deeply about my safety. But never once did I leave my well being in their hands.
One employer said that lift truck drivers and pedestrians (factory worker) were each responsible for looking out for each other and they had guarded cross walks and flashing lights for lift trucks everywhere.
My other employer said “Assume that the lift truck driver is trying to kill you”.
Guess who never had a death or even serious injury?
I believe the USPS does the same.