A fire at an electrical sub station behind Holloway Road tube station caused severe delays to the Piccadilly line.
More than 30 firefighters tackled the blaze near the station in north London this morning.
Six crews from Islington, Holloway, Stoke Newington, and Kentish Town fire stations were called to the scene just before 9am and the fire was under control by 10am, the London Fire Brigade said.
People in the area reported smelling burning plastic.
The cause of the fire, which caused a power outage at the station, is being investigated.
The brigade's deputy assistant commissioner Graham Ellis said: "Firefighters worked hard to bring the fire under control in order to minimise disruption to trains in the area."
There was no service between Rayners Lane and Uxbridge for most of today due to a power failure at the station.
For a short time Victoria line trains were not stopping at Finsbury Park station, which was also closed as a result of the power failure, but a normal service has since resumed, Transport for London (TfL) said.
Hornsey Street was closed at the junction with Holloway Road while emergency crews investigated, but it has since been re-opened.
