Well, at least I'm sure we learned some valuable less-

The story made national headlines, and Crush was immediately "fired" from the Katy Railroad.[12] In light of a lack of negative publicity, however, he was "rehired" the next day and continued to work for the company until his retirement, in a career spanning six decades.[13]

Incredible

That was my reaction too. However:

Katy engineers assured Crush that his grand idea was safe, specifically that the boilers on the steam engines had been designed to resist ruptures and that, even in a very high-speed crash, they were unlikely to explode.

But the question remains: What made the engineers sure that the design was safe?