If you are flying from mainland USA to Alaska, but the plane crashes?
If your plane crashes in British Columbia on the way to Alaska it will be either into the ocean or in territory like this. The likelihood of survivors are close to zero. Regardless, US Officials will be part of the search team for a US aircraft and they will take care of any survivors paperwork. However American survivors, if any, will still be taken of medically as required and who pays the bill will be discussed much later. In cases where a plane has a mechanical problem and lands at Vancouver, Comox or Prince Rupert (Those are the only airports to speak of that can handle jets) the passengers will be disembarked into a secure area in the terminal. They will he held there, with access to restrooms, food, drinks and wi-fi until a replacement aircraft can come up from Seattle to pick them up. From Vancouver they may also be bussed to Seattle. Whatever the airline decides. US Immigration and other officials are immediately available in Vancouver. Within a couple hours at the other places. THis all happens rarely but often enough that there are fully thought out procedures in place. We have had incidents where a Canadian domestic flight cannot land at Vancouver or Abbotsford because of extra heavy fog and they have diverted to Seattle. With many Canadians on board without passports. Again, there are well planned procedures in place and the passengers will either wait in the terminal in a secure area until the flight can proceed to Vancouver. Or they will be bussed to Vancouver BC.