You know... I feel for Arihito and Kyouka for dying, but in a way, they were adults they already had lived a little of their lives enough to have some things figured out or simply experienced a few things... but the teens.
They are kids, they had family and friends, I mean... just think about what Suzuna's parents must be feeling after losing their daughter, and the other girls too.
They had an entire life to live, and now they have to deal with this strange world.
Sure they at least have a new little family to be part of, but even then just thinking what their families must be feeling is heartbreaking.
Ribault is really an awesome dude, deciding to focus his effort and team to help newcomers adapt and survive this new life, that is some Chad mindset.