Some 60,000 homes and businesses across Sydney's west lost electricity about 4:00pm when the power outage occurred, blacking out suburbs including Campsie, Ashfield and Earlwood. The outage affected up to 100 sets of traffic lights, sending traffic at intersections into chaos. The Transport Management Centre (TMC) said most of those lights are working again but motorists are advised to exercise caution through intersections where traffic lights are still blacked out. "People really need to take extreme care and follow directions of police manning key intersections in these areas," the TMC's Bronwyn Martin said. Power crews on their way to carry out repairs were also affected, having to battle through Sydney's infamous peak-hour traffic. Ausgrid said the blackout was caused by a faulty piece of equipment inside the Canterbury substation and crews were still there investigating. The M5 which was earlier closed between Mascot and Bexley North, has now been opened in both directions. The light rail services between Lilyfield and Dulwich Hill have also been restored, but people are asking people to allow for more time as traffic remains heavy. The TMC also advised people travelling to Sydney Airport to catch a T2 Airport Line train. Many bus services are delayed up to 40 minutes with traffic still backed up in some areas. There is no forecast for when the M5 East will reopen.