Cable modems drop offline en masse, triggering a torrent of alarms at cable headends and monitoring systems. As the cable office goes dark, all of the phones go silent, monitors fade and employees look at each other in disbelief. They wait for a word from their supervisors about what to do. Moments later, the Nextel phones begin to chatter. Dispatch is calling technicians to notify them of the blackout.
Technicians call in, as they notice both streetlights and restaurants are now dark.
Maintenance supervisors and the engineering manager drop what they are doing and respond to the emergency. I m not sure. In the older classic cable system, the trunk systems should have switched to standby. The headend power generator should have started and transferred the load. Of course, this is after all power sources went off.