Tens of thousands of Londoners were left without power after a fire at an electrical substation on Tuesday which also caused rush hour transport chaos.
The London Fire Brigade (LFB) said it had been called to a blaze in Castor Lane, Poplar at 12.48pm, which by Tuesday evening had been extinguished.
The brigade said up to 4,500 customers had been affected by power outages due to the blaze which damaged the ground floor of a two-storey substation - although the cause of the fire remains unknown.
It is understood the power outage also affected the communication and signaling services at the Blackwall, Limehouse and Rotherhithe tunnels, which caused them to be closed earlier in the day.
As of 6.45pm the Blackwall Tunnel had reopened while the Limehouse Link and Rotherhithe Tunnel also opened during the evening.
Station Commander Colin Digby, who was at the scene, said: “Firefighters worked hard in challenging conditions to bring the fire under control.
"The fire has caused power outages in the area, affecting around 4,500 customers. The Limehouse Link Tunnel and Blackwall Tunnel has reopened. The Rotherhithe Tunnel remains closed."

Ten fire engines were called to the scene while there are also 70 firefighters working to put the blaze out, the brigade has said.
There are now 10 fire engines and around 70 firefighters at the scene of the fire in #Poplar. Crews are continuing to work to bring the blaze under control https://t.co/JawGxtqFQl pic.twitter.com/BohOca9SpB
— London Fire Brigade (@LondonFire) March 29, 2022
Around 100 people were evacuated from an adjacent depot and 1,500 students were evacuated from a college at the rear of the substation, the brigade said.
Large electrical fire causes HUGE East London powercut - POPLAR, LONDON
— Jamie Lashmar (@senewspics) March 29, 2022
Watch here: https://t.co/jAD1O6Um3A pic.twitter.com/JMTgE2IAo4
Labour councillor for Rotherhithe, Bill Williams previously said: “Please avoid all routes relating to the Rotherhithe Tunnel SE16.
“It's closed in both directions due to a fire in Poplar at an electrical substation.”
Looks like someone forgot to top up the meter in east London today. Not a signal traffic light working, blackwall tunnel closed and DLR down 😁. I just wanna get to the O2
— Nicholas Lee (@Lee01Nicholas) March 29, 2022
UK Power Networks also confirmed areas in east London had suffered outages although their own outage map showed cuts in multiple areas across the capital.
UK Power Networks said: “We’re aware of a power cut affecting the E1, E1W and E14 areas of London.
“Our engineers are working to get the power on as soon as possible.
“For the latest information in your area visit our power cut map.”
We’re aware of a power cut affecting the #E1, #E1W and #E14 areas of #London. Our engineers are working to get the power on as soon as possible. For the latest information in your area visit our power cut map https://t.co/3Mde2WUSDf
— UK Power Networks (@UKPowerNetworks) March 29, 2022
While a nucleus of outages were reported in the Whitechapel area, there were also clusters of reports in Belgravia, Westminster, Pimlico, Brixton and Wimbledon.