A signal failure at St Pancras Station caused travel chaos and delays of up to 30 minutes in South London this morning.
All train stations in the Wimbledon loop were affected, including trains travelling through Streatham, Tooting, Wimbledon and Sutton.
The signal failure, which started at 7.40am, caused trains to back-up behind each other in St Pancras.
Commuters faced delays of up to 30 minutes, while a number of services were diverted from Streatham to Wimbledon.
There were also part cancellations.
A spokesperson for First Capital Connect said it was cleared by 9.20am, with knock-on affects lasting for some time afterwards.