They say the electricity doesn't work and then Captain Man turn on the cameras to look at Charlotte and Jasper. Correction: They say all transmitters and receivers are blocked, nothing about electricity.
While on lockdown in the Man Cave, the group makes a campfire to roast marshmallows. Seeing that the emergency shutdown system is set to run for two days while the generators aren't designed to make it past the first day, it's also likely that the short-sighted system can't handle the smoke from an open indoor flame campfire, thereby suffocating those inside.