Surely an elegant engineering solution would have saved lives in this instance? I think you mean one is not required for all the times that people don't die. Then it's just redundant.
What engineering solution would have prevented this driver's death? She knew a train was coming from the bells, flashing lights, and closing gates. She had at least 30 seconds to react.
If you mean a more elegant solution -- a different 3rd rail design, e.g. -- would have saved the lives of the people aboard the train, that's possible. In the event of a mutli-ton train at 60MPH hitting a multi-ton truck sitting on the tracks, we should not presume that's the case.
The better scenario is to heed the bells, flashing lights, and protective gates and get off the tracks. It's a difficult engineering task to ensure people heed clear warnings.
A solution like the one mentioned higher up - which physically blocks entrance (though allows exit) a longer time ahead, and also automatically warns train drivers that there is something blocking the line and prompting them to slow down a reasonable distance ahead.