There are severe delays across the Tube network this morning, with services disrupted on the Victoria Line, the District Line, and (of course) the Piccadilly Line.
There is currently no Victoria Line service between Brixton and Victoria due to a signal failure at Brixton, with severe delays on the rest of the line.
And Transport for London warned commuters to avoid using Brixton station as it is "very congested" due to the signalling problems and the Southern rail strikes.
On the District Line there are severe delays between Earl's Court and Richmond/Ealing Broadway, with minor delays on the rest of the line due to an earlier signalling problem in the West Kensington area.
Meanwhile, on the Piccadilly Line, delays due to a shortage of trains are ongoing. Transport for London said there are shuttle bus services in operation in some areas around the line.