For the tower portion - the Nova 2.0 zombies seem to be electrified, what about killing a bunch of them at the tower? That would make things dicey but if we have to power it up and these things are electrified then it may work? Just a thought.
Or maybe Richtofen? Because that distressed girl said she was unable to hear the german mans voice any more. Maybe he's communicated with a few people and the flesh eating group progressed farther than the distressed woman.