Kathrine Vail:

Her question went unanswered as an explosion went off at the front of the group. Kat reacted on instinct, throwing herself and hopefully Amber against the wall as best she could.

 There were any number of lifeforms that used some manner of explosive chemical compounds as a means of self defense. In confined spaces like this, a sizable explosion could send shockwaves and any number of harmful material ricocheting down the space. Depending on what had gone off, things could get... Messy. 

Sure enough, Kaze came flying down the hall a ways, before literally screeching to a stop. Cassius gave an order, one which Kat herself might have assisted with, had there not been a dragon and at least two men between herself and the intended 'pasting' targets.