In the aftermath of the Decimation event known as M-Day, the mutant student body in the academy dropped from 182 to 27. At least 45 depowered students were killed and, of the remaining students, Emma Frost picked a select group to train as New X-Men. These were Surge (appointed leader), Elixir, Hellion, X-23, Rockslide, Mercury, and Dust. As time progressed, several members were added and/or earned the right to be on the team, such as Prodigy, Anole, Armor, Pixie, and Gentle. The rest of the students were instructed to remain on school grounds, some providing assistance to the current X-Men teams and trainees. Some M-day survivors and depowered students either left the mansion or were killed off during villainous attacks by Stryker and his men, or various other enemies.
Read more about this topic: New X-Men