Approximately 50,000 properties were left without power in the Portsmouth area after a "network fault" took a key substation offline.
The incident plunged the naval port city and nearby towns into darkness shortly before 9pm yesterday, leaving homes and businesses pitch black and forcing locals to navigate some roads without streetlights. One Portsmouth resident who lives alone said the experience was quite "frightening".
Images posted on social media showed Portsmouth's landmarks including the Spinnaker Tower and Gunwharf Quays only dimly lit by safety lighting. This video shows the library at the University of Portsmouth in darkness.
SSE said it was investigating the cause of the blackout. A company spokesman said: "We had a network fault at the primary substation which caused roughly 50,000 properties to be without power from just before 9pm last night and we got them all back on just after 9.30pm."
The incident took a primary substation offline, which in turn affected smaller substations, leading to the widespread loss of power.