On Thursday morning commuters were hit with signal failures that affected four tube lines across the London underground causing chaos.
No service between Baker Street and Aldgate due to a signal failure in the Aldgate area. Tickets valid on local buses.
— Metropolitan line (@metline) April 18, 2019
The Metropolitan, The Circle, District and Hammersmith and City lines were affected with severe delays. Trains heading to Heathrow were affected dues to another failure between Paddington and Hayes and Harlington.
Due to a fault with the signalling system TfL Rail and Heathrow Express services were delayed by 15 minutes, due to a signal fault between Acton Main line and Paddington.