Well, where Madwa is, is dead.
Do the others have any way of knowing that? And, if so, would knowing it lead them to clear out?
And who does important lab work in a room with stuff dangling from the ceiling which might fall down into the work at any moment? Wouldn't they have had minions knock the loose stuff down and sweep it out of the way first? Or is that supposed to be damage done by the explosives that opened the door -- which, come to think of it, might also have led everybody to vacate the lab?