According to the Transport for London site Brixton Tube Station is closed due to…
No service between Warren Street and Brixton while we fix damage caused by Flooding at Victoria. SEVERE DELAYS on the rest of the line. Tickets valid on South Eastern Trains, South West Trains, Greater Anglia, First Capital Connect (Great Northern), London Overground and London Buses via reasonable routes.
However, according to the usvsth3m web site, this was caused by a civil engineering team who poured fast-setting concrete into the signalling equipment room…
Who do you believe?