May I quote Chesley Sullenberger? (Captain of Cactus 1549, who with F/O Jeff Skiles, was forced to land in the Hudson river after a double engine failure).
"Everything we know in aviation, every rule in the rule book, every procedure we have, we know because someone somewhere died....
We have purchased at great cost, lessons literally bought with blood that we have to preserve as institutional knowledge and pass on to succeeding generations. We cannot have the moral failure of forgetting these lessons and have to relearn them."