Commuters were braced for rush hour chaos on Thursday morning after signal failures caused chaos across the London Underground.
The Circle, Hammersmith and City, District and Metropolitan lines were all severely delayed or suspended after a signal failure near Aldgate.
Trains to Heathrow were also affected after another signal failure between Paddington and Hayes and Harlington.
The District line was running with severe delays, while the Circle line was completely suspended.
There were no Hammersmith and City line trains between Moorgate and Barking, with severe delays on the rest of the line.
The Metropolitan line was also affected, with no service between Baker Street and Aldgate but with a good service on the rest of the line.
TfL Rail and Heathrow Express services were delayed by up to 15 minutes because of a fault with the signalling system between Acton Main Line and London Paddington.
Trains are also unable to call at Hanwell in both directions, with disruption expected until 8.30am.
Commuters were being advised to take local buses.
