A major power cut has hit parts of <a href="https://www.thenationalnews.com/tags/london/" target="_blank">London</a>, causing traffic light failure and interruptions to internet access and water supplies for more than 5,000 people. UK Power Networks said more than 42 postcodes were affected in the capital on Tuesday. Homes, businesses and streets in the east of the city were hit particularly hard, but the blackouts also spread to Cricklewood in north London and <a href="https://www.thenationalnews.com/tags/wimbledon/" target="_blank">Wimbledon</a> in the south. “We’re aware of a power cut affecting the E1, E1W and E14 areas of London,” the group tweeted. “Our engineers are working to get the power on as soon as possible.” The power cuts were caused by a fault on a high-voltage underground electricity cable, UK Power Networks said. The energy company owns and maintains electricity cables and lines across London, the south-east and east of England. Staff said engineers were having "access issues to some equipment" and therefore there had been a delay in offering an estimated time for the power to return. The company later said it expected customers would have their power back by about 3pm. Internet services and traffic lights went down at about 12.30pm on Tuesday and taps ran dry. People working from home were hit particularly badly by the power cuts. Resident Lauren Sherrell said the power cut had left her without access to a lift in her building. “Please get it back on ASAP I have to walk an autistic child in a pram up 13 flights of stairs if no lifts still by time he finishes nursery,” she tweeted. Another person said traffic lights in the east London borough of Tower Hamlets were down. “This power cut has taken out a good number of traffic lights in east London,” they wrote. “But I have faith that the extremely sensible drivers of Tower Hamlets will be able to tell difference between a green light and no light.” The Docklands Light Railway suffered delays on Tuesday afternoon “due to an earlier major power failure”, a status update on <a href="https://www.thenationalnews.com/world/uk-news/2022/03/01/strikes-and-fare-hikes-how-public-transport-in-london-went-down-the-tubes/" target="_blank">Transport for London</a>’s website said, after the line had been completely suspended. The Blackwall and Rotherhithe tunnels connecting east London to the south of the city and roads in the Poplar area were closed after a fire at an electrical substation. London Fire Brigade said the blaze at the site in Castor Lane, Poplar, had caused power cuts for up to 38,000 customers. Four engines and 25 firefighters were dispatched to tackle the flames and a 25-metre cordon was set up. About 100 people were ordered out of an adjacent depot and 1,500 students were escorted out of a nearby college after the ground floor of a two-storey electrical station went up in flames. Pictures posted on social media showed smoke rising above complex. Station Commander Colin Digby, who attended the scene, said: "The fire is causing power outages which could affect around 38,000 customers. "The whole of the Docklands Light Railway line is suspended. Blackwall Tunnel and Rotherhithe Tunnel are also closed whilst crews work to make the scene safe." The brigade said the closure of roads and tunnels would likely worsen rush hour traffic on Tuesday afternoon. The cause of the fire was not immediately known and there were no injuries reported.