It wasn't an accident. It was deliberate. For 8 minutes every soul onboard knew that the pilot was flying them into the ground. The desperation of the pilot to get into the cockpit must have been overwhelming.
With nuclear weapons we had two person integrity. There would never be one lone person with a nuke. We actually called it a no lone zone. With crypto we had two person integrity. After Walker there would never again be one person alone with bulk encryption material.
I think the airlines have just joined my two worlds. We will never again have a lone pilot in the cockpit. Those days had better be over.
Shattering awful accidents are something that one can lay at the feet of one's God. Narcissism so cruel that it takes away everything in the world, that's probably unendurable. A word of Grace may be in order.