Every emergency support system we have is built on "the internet" backbone. Sure, DNS servers can be taken down, major ISP can be forced offline, but if there were a single internet kill switch, the backup systems (paper/pen) would be overwhelmed in hours.
Hospitals, City Hall, Police Stations, Fire Depts, EMS, FAA, Vault Security Systems, so on and so forth.
The idea of a complete comms outage for 10 days is coming from fear. I dwelt upon it for a while too, and then began to think logically. Not gonna happen.