Next door are the huge generators which kick in in the event of a power cut.

BBC: A final look at GCHQ's top secret Oakley site in Cheltenham

In the event of a prolonged power blackout, backup generators frequently run out of fuel or suffer performance problems when they operate continuously for more than a few days.

FORBES: Backup Generators Are the Bad and Ugly of Decentralized Energy

Several other non-nuclear power generators along the East Coast were tripped, meaning they were automatically shut down by the seismic event.

FORBES: Power Prices Spike after East Coast Earthquake