I feel really bad for the pilot and copilot, who were forced to kill themselves and a bunch of others because a powerful psychopath took over the cockpit and forced them to fly into the ground.
I mourn the deaths of Captain Robert Frisbie and First Officer Peter Kowalczyk. Poor Captain Frisbee particular was not getting out of this - either he died, or he was going to be fired, as if he'd done the right thing and diverted, the psychopath would have gone out of his way to destroy him and, "But I saved you from a terrible death," would have had less than zero value.
I mourn exactly these two human lives lost in this crash. Also, it's unfortunate that the plane was destroyed, as this causes pollution and is a waste of resources - and I'm sad that some trees were destroyed too.