What happened and when will flights be back to normal?

Flights around the world have been disrupted after Heathrow Airport closed due to a fire at a nearby electrical substation.
Heathrow, the UK’s busiest airport, said on Friday afternoon that they will “restart” some flights later after the blaze at North Hyde substation in Hayes, west London. The airport said it hoped “to run a full operation” on Saturday,
More than 1,300 flights were affected, tracking website Flightradar24 said, and passengers have been told not to travel to the airport unless their airline has advised them to.
The National Grid said earlier that an “interim solution” has been found to allow power to be restored to customers including Heathrow Airport, saying that the network has been “reconfigured to restore all customers impacted”.
Here’s what we know so far.

Courtesy: BBC