The information on refund/voucher is very useful. I had thought that if I cancel the trip at short notice for any reason, I would forfeit the money. As SoS has asked, it would be nice to know exactly what triggered the Esta cancellation but i would guess we won't be told. It does look as if it would be as likely to be cancelled at the terminal check in as on line under the current rules and until the proclamation is rescinded, one's Esta needs to be replaced by a proper visa. Commiserations to your relatives but thank you for sharing this sad story.