National Rail has revealed that passengers can expect delays of up to two hours as a result of the incident. Delays are being experienced on multiple routes operated by TFL (London Overground), London Northwestern, Southern and Avanti West Coast.
National Rail said: “The emergency services are dealing with an incident between Watford Junction and London Euston. So that they can safely carry out their work, all lines are closed.
“As a result, trains operating between these stations may be canceled or delayed by up to 120 minutes. Major disruption is expected until the end of the day.”