The course of events can sometimes be incredibly subtle.
When Marcus Monroe saw the fragments of iron shackles and glanced at the demolished laboratory—now a pile of ruins open to view—he was somehow reminded of the underground lab in Norgate. A thought struck him, and he immediately called over the team's Earth Ability User to give him some instructions.
At the same time, he began calling over members of The Research Institute's Guard to ask if they had found any survivors.
If they had told him the truth, he would have certainly gone to the medical department for a look, and he would have found Paige Summers... But as fate would have it, they had been instructed by Vice Dean Sawyer to conceal the existence of any survivors.
Furthermore, Seth Walsh's face was smashed beyond recognition. As for the others, like Professor Warren, they were strangers to him and had no apparent connection to Paige Summers.
