Can I just add, Delta does the humanitarian thing very well? I've had two instances where they waived the change fee. One involved a funeral. The other was a Major Medical Incident while I was on the road, and was told by the doctor in no uncertain terms that I would be traveling home as soon as I was somewhat stable, and would not be continuing along my planned itinerary. Not only did Delta waive the change fee, they waived the (not insignificant) price difference to rewrite my ticket to get me straight home.

Yes, they're a business and they have fees and upcharges. But during one of the scariest episodes of my life, they went above and beyond what I could reasonably have expected.