Firefighters battled a blaze on the train tracks in Putney today.
They were called to the fire at about 12.30pm, with Putney station being forced to close.
It is believed the fire was caused by a faulty cable on the track.
Commuters also faced delays on the District Line and trains to Waterloo travelling from Clapham Junction.
South West Trains said trains are being delayed up to 95 minutes due to signalling problem, with no idea when normal service will resume.
Angry travellers have been posting there complaints on Twitter.
Jade Pearn wrote: "The district line is suspended Wimbledon/Putney Bridge, power failure - Wimbldeon area. Of course there is."
Tim Rolls said: "Transport fiasco update: In addition to train problems @ Clapham Jct, no tubes between Putney Bridge and Wimbledon due to local power failure."
A spokesman for the Network Rail and South West Trains Alliance said: “A major power failure has resulted in a widespread loss of signalling and traction, meaning services in and out London Waterloo are currently being heavily disrupted.
"Services on the mainline route from London Waterloo are currently running but are disrupted and subject to delay and short notice cancellation. I
"It is likely that a reduced number of services will run on this route throughout the afternoon and further details of the planned service alterations will be made available shortly."