> This did not happen when we were inventing cars, trains and air planes.

Cars are small, and they still go up in flames routinely all on their own (for older cars, aged fuel lines rupturing is a top cause, for newer cars shit with the turbocharger), it just doesn't make more news than a line in the local advertisement rag because usually all it needs is five minutes work for a firefighter truck.

Trains had quite the deadly period until it was figured out how to deal with steam safely - and yet, in Germany we had the last explosion of a steam train in 1977, killing nine people [1].

[1] https://de.wikipedia.org/wiki/Kesselzerknall_in_Bitterfeld