Traffic queues in San Diego due to power outage
Media playback is unsupported on your device
Video

San Diego grinds to halt as US hit by power blackout

Power is steadily returning to two southwestern US states and Mexico, following a massive blackout which affected more than five million people.

Services to Arizona were restored early on Friday, while parts of California and the Mexican state Baja California have also since been reconnected.

Michael Niggli, president of San Diego Gas and Electric, earlier said both main connections of electricity into the city had been severed.