I am curious about the legal status of the victims of the crash as well.
As it happens, I ran into an analogous situation recently with an acquaintance who is an EU citizen in the USA under the VWP. While visiting the USA, he briefly left the country by sea to go on a cruise to the Bahamas, where he disembarked and spent a few days (and was stamped in by immigration officials there). Upon returning to the States, he simply walked off the cruise ship...no CBP officers inspecting, no port officials checking passports, nothing at all. He is worried that CBP will have no record of his re-entry to the USA, and that it will cause problems when he tries to depart the country by air later in the month.
What do you think he should do? Go to an airport and speak with the CBP officers? Call the cruise line? Hope that the cruise line submitted pax info properly and cross fingers?