There is major disruption on rail lines in and out of King’s Cross after a person was hit by a train earlier today.
Emergency services were called following reports a person had been hit by a train between London and Stevenage.
Services between King’s Cross and Bradford, Sunderland, Letchworth Garden City, Cambridge, Hull, Beverley, Harrogate, Newcastle, Edinburgh and Glasgow have been impacted.
Trains may be cancelled, delayed by up to 60 minutes or revised, with disruption expected to last until the end of the day.
Meanwhile holidaymakers travelling to Heathrow face major travel disruption as a four-day Piccadilly line shutdown gets under way.
There is no service between Acton Town and Heathrow Terminal 5 while Transport for London carries out track upgrades and prepares for the introduction of its new train fleet.
A points failure at Whitechapel has also resulted in tube chaos, with suspensions on the District, Circle, and Hammersmith & City lines.
If you've been affected by what happened on the network today, there is always someone to talk to. You can contact the Samaritans on 116 123 from any phone for a confidential chat.
Follow our live blog for the latest travel updates throughout the day.
Points failure at Whitechapel causing Tube havoc
15:08 , Tom Place
A points failure at Whitechapel is causing a number of underground lines to be severely delayed or suspended.
The Circle line is currently fully suspended due to the issue, while there is no service between West Ham and Whitechapel and severe delays between Tower Hill and Earl's Court on the District line.
There is also no service between Liverpool Street and Barking on the Hammersmith & City line, and severe delays on the rest of the line.
Reduced service on Windrush and Mildmay lines
14:57 , Tom Place
There is a reduced service on both the Windrush and Mildmay lines today due to a shortage of train drivers.
There has also been a fault with the signalling system between Surrey Quays and Clapham Junction on the Windrush line causing further disruption.
Clapham Junction services are cancelled southbound, but additional services may run between Surrey Quays and Dalston Junction.
Disruption remains around King's Cross
14:47 , Tom Place
Lines have now reopened following a person being hit by a train between London and Stevenage earlier this morning.
However, trains may be cancelled or delayed by up to 60 minutes whilst services get back to normal.
The major disruption is expected until the end of the day.
Rail replacement buses are in place
11:58 , Megan Howe
Great Northern and Thameslink have been able to put some replacement buses in place, so passengers can use these to continue their journey.
These buses will operate between Welwyn Garden City and Stevenage.
Which services out of King's Cross are affected?
11:32 , Megan Howe
National Rail has said the following routes are affected this afternoon:
• Grand Central between London Kings Cross and Bradford Interchange / Sunderland
• Great Northern between London Kings Cross and Letchworth Garden City / Cambridge and also between Moorgate and Stevenage
• Hull Trains between London Kings Cross and Hull / Beverley
• LNER between London Kings Cross and Bradford Forster Square / Harrogate / Newcastle / Edinburgh
• Lumo between London Kings Cross and Edinburgh / Glasgow Queen Street
• Thameslink between Brighton and Cambridge and also between Horsham and Peterborough
Major disruption at London's King's Cross
11:31 , Megan Howe
Major disruption is expected at King’s Cross after a person was struck by a train between London and Stevenage.
Emergency services are currently at the scene, and all lines between these stations have been closed to allow safe access for paramedics.
As a result, train services in the area are subject to significant disruption.
Services may be cancelled, delayed by up to 60 minutes, or revised at short notice.
Major disruption is expected to continue until approximately 3pm, with passengers advised to check before travelling and allow extra time for their journey.
Windrush line is part suspended
09:05 , Megan Howe
The Windrush line is part suspended this morning between Surrey Quays and Clapham Junction due to a signal system failure.
Good service on the rest of the line.
Lightning strike near Crewe forces services into London Euston to cancel
08:39 , Megan Howe
Rail services to and from London Euston are facing disruption as the extreme weather has caused damage to signalling infrastructure in the north.
A lightning strike between Crewe, Liverpool South Parkway, and Warrington Bank Quay has led to the closure of all lines in the area while repairs take place.
Services operated by Avanti West Coast and London Northwestern Railway are affected, with delays and cancellations expected across routes linking London with Birmingham, Glasgow, Edinburgh, Preston, and Liverpool.
National Rail has warned that delays of up to 30 minutes are likely, with disruption expected to continue until the end of the day.
The situation comes during a UK heatwave, which is also putting pressure on transport networks and increasing the risk of further delays.
Passengers are advised to check journeys before travelling and allow extra time.
What is happening on the Piccadilly line?
08:19 , Megan Howe
Piccadilly line passengers have been warned about planned closures throughout the summer, with upgrade work ramping up ahead of the introduction of a new fleet of trains.
The closures will allow essential works to the line’s infrastructure to be completed, including upgrades to its power supply, tracks, depot, platforms and CCTV system.
The partial closures have been mostly planned for weekends, with suspensions running through the Friday Night Tube to the end of Sunday service.
Piccadilly line faces summer of closures to test new trains - see full list of dates
Minor delays on the District line
08:14 , Megan Howe
There are minor delays on the District line between Earl's Court and Ealing Broadway/Richmond due to an earlier faulty train at Victoria.
Severe delays on the Bakerloo line
07:35 , Megan Howe
There are severe delays on the Bakerloo line this morning due to a late finish of engineering works.
Tickets are still being accepted by London Buses.
Elizabeth line really busy this morning
07:21 , Megan Howe
Commuters are already reporting that the Elizabeth line is especially busy this morning, with packed carriages and passengers struggling to get a seat.
It’s likely to be a knock-on effect from the partial Piccadilly line closure, as travellers look for alternative ways across the capital.
So if the Elizabeth line is part of your commute today, it could be worth allowing some extra time to complete your journey.
We will update you on the situation at rush hour.
Part closure on the Piccadilly line starts today
07:13 , Megan Howe
A four-day partial shutdown of the Piccadilly line has started today, causing major disruption to passengers travelling to and from Heathrow Airport.
There is no service between Acton Town and Heathrow in either direction, with rail replacement buses running instead.
Travellers are being urged to allow extra time or use alternative routes as disruption is expected to continue through to Sunday.
The closure will allow engineers to carry out major upgrades to the line’s power systems, tracks, platforms and depots ahead of the rollout of TfL’s new fleet of trains.
Transport for London is also carrying out extensive testing to ensure the new trains can run safely and reliably on parts of the network that are more than 100 years old.
