UK Power Networks has apologised to thousands who have spent the night sitting in the dark after major power outages.
The power cut hit at least 38 postcodes, affecting houses in Stanmore, Harrow, Wembley and Borehamwood.
People in Lincoln were also said to have been without power for a time this evening too.
The issues affected phone lines as well as people’s lights and tellies.
Some went online to joke it is lucky they had their Valentine's Day candles ready while others fumed they were missing the NFL Super Bowl.
National Grid ESO said in a tweet: “We apologise for the disruption to consumers in North West London who have been disconnected this evening.
“Some have already been reconnected and engineers are working hard to ensure that all consumers are reconnected as soon as possible.”
Several people posted images of themselves sat in the dark waiting for power to return while others fumed at the delay.
One unhappy customer said: “Power cut in Wembley. Looks like Harrow and Stanmore affected too.”
It is understood some of the affected homes had their power resumed at around 9.30pm.
A statement UK Power Networks said: "An underground electricity cable faulted on our high voltage network, causing an area wide power cut.
"We are working to restore power to the remaining 135 customers affected.
"We believe the cause was a transmission issue, and investigations are continuing."
One impressed customer later said: “I think it's mindblowing that a single fault can be so important, but even more mindblowing that we can fix it within minutes for the most part, hours for most others, and we can get real-time updates wherever we are.
“Great job all.”
