Trainwrecks, uncommon as they are, actually kill fewer people even when they occur than the word would imply. Modern trains are very sturdy creatures, built so you don't die even if they get derailed. Even if the tunnel you're passing under collapses around you - the structure is meant to protect the passengers until they can be extracted.

There are exceptions. Some trainwrecks kill people. A train which is poorly maintained, on track poorly maintained, caught in a rockslide - that can kill people.

The parents of the Pevensie children were not the only fatalities of this trainwreck. They're just the ones most relevant to the Pevensie children, currently climbing out of a state employee's car and heading towards the door of Evelyn Steel.