At 22:45 on 5 December 2015, the River Lune flooded through Lancaster and the electricity supply to 61,500 people failed. What happened next is now the worked example behind the UK's emergency planning for a total communications failure.
Roger Kemp, a professor at Lancaster University, was watching television when it went. "Streetlights were off. The sodium glow that we can see over the horizon from Morecambe was off," he told the BBC. "[It was] almost like a zombie movie. People trying to find phone reception, wondering where things were, and there was a huge queue at the one working telephone box."
What stopped, and how fast
The list is worth reading in full, because it shows how much depends on electricity rather than on any communications network.
Households lost light and heat. Some water supplies began to fail, because they relied on electric pumps. The railway station closed. Petrol stations and shops closed. Most cash machines stopped working. Traffic lights failed.
None of that is a communications failure. It is what happens when power goes and everything downstream of power goes with it.
The two things that survived
Only two communication systems kept working: copper wire landline telephones and FM radio.
The local commercial station, The Bay, had an emergency generator and one landline. It sent a reporter outside the affected area to telephone information in. That is the entire emergency communications architecture of a modern British city during the event — a generator, a copper line and a reporter in a car.
Why that lesson is uncomfortable now
Both survivors are being retired. Copper landlines are being switched off across the UK in favour of internet-based telephony, which needs mains power at the customer's end and a working broadband connection. FM radio is in long decline in favour of digital.
The replacements are better in every ordinary respect and worse in exactly the circumstance that matters here. A copper phone draws its power from the exchange and works when your house has none. A fibre line with a router does not.
That is the gap BlackSky is meant to address — not a cyber-attack scenario but a physical one, where the question is not who did it but what is still standing afterwards.
Why a Bangladeshi reader should care
This is not a distant British problem. Bangladesh has more experience of power failure than Britain does, and the same substitution has been under way here: landlines abandoned, mobile and broadband relied on, both dependent on tower power and backhaul.
The 2015 Lancaster list — pumps, tills, traffic lights, fuel — describes any city where electricity fails for long enough. The useful question the report raises is not whether a backup exists at the national level, but whether anyone in a household knows what in it would still work on hour six.
What a household can actually do
National resilience planning is not something a reader can influence. Three cheap things are.
A battery or wind-up FM radio costs very little and works when nothing else does — which is exactly why The Bay mattered in 2015. A power bank kept charged extends a phone past the point where the tower may still be running. And knowing where the nearest working payphone or landline is sounds absurd until the hour it does not.
None of that is preparation for catastrophe. It is the difference between being informed and being one of the people queuing at a phone box wondering what happened.
