Someone or more than one were not paying attention for something like this to happen.
It’s indeed unfortunate, but you nailed it.
Baring some explanation that the truck was somehow snagged on the tracks, which is very doubtful, this truck should not have stopped on the tracks.
If it couldn’t fit on the other side, it should have stopped before crossing the tracks.
If other people are trusting you with their lives, it is vitally important you be thinking every moment on the job you have been tasked with.
This is just tragic. And it’s even more-so because it should never have happened.
In many parts of Texas, you can see a train coming from a great distance. I’m not sure about this exact crossing, but I wouldn’t be surprised if you could.