Since this was over 40 years ago, and the facility involved was demolished (probably in the 70s), it's probably safe to retell now: I was monitoring the road channel in San Bernardino, and one of the tower operators had called a UP train (running on trackage rights over Santa Fe) on the radio. "UP Extra 3645, stop short of the 19 block." (a few seconds later, with more firmness) "UP Extra 3645, stop short of the 19 block." (a few more seconds went by) "UP Extra 3645 FOR GOD'S SAKE STOP!!!!"