an infection has broken out. Abbie, Lana and Claire are the ones who got infected (unable to defend themselves) and other background character students..

The Principal, Miss Grace, is obviously stressed and troubled

Miss Grace: Everyone settle down.. You're making this harder for me...

Everyone was panicking, Miss Thavel, Miss Bloomie and Miss Circle did not however panic. Oliver, Zip and Edward too did not panic, everyone else was

Engel: ...Claire.... he looked to be saddened by Claire getting infected