Re: I dont understand why cutting a single cable takes out an area
The internet might be able to re-route things when something happens.
Firstly this was not just a "cut".
It is not until you get deep inside a ISP's network that the multi honed benefits can take over.
From you to the Street Cab is one connection. From there it's a single connection back to some form of headend and it's possible that more than one headend is connected in a ring allowing some redundancy. Once you reach the core network from the headend then there should be multiple points of redundancy.
The core network will have multiple peering providers in multiple peering locations. Really small ISP's might only have one provider.
The fact that the post above yours shows that multiple ISP's were down including mobile networks (They probably use Fibre backhaul instead of Microwave) shows just how much was "cut".