Rail travellers using London Euston station are facing severe disruption following a fire overnight at a timber yard and offices in north-west London.
The line is closed between Milton Keynes and Euston, affecting routes to the Midlands, north of England, Scotland and North Wales.
Engineers are repairing fire damage near the affected line, which Network Rail expects to re-open this evening.
The fire is still burning but under control, London Fire Brigade said.
Network Rail said the blaze had left a trackside retaining wall “in danger of collapse” and it would “need to be dismantled, made safe and rebuilt”.
Engineers have already started dismantling the damaged wall, but the West Coast main line will remain shut between Euston and Milton Keynes while the repairs are made, according to Network Rail.
- London Midland, Virgin Trains and Southern rail services are unable to run between Milton Keynes Central and London Euston
- Virgin Trains to and from Scotland, north-west England, the West Midlands and north Wales are starting or terminating at Milton Keynes
- Southern services between Milton Keynes Central, Watford Junction and Shepherds Bush have been cancelled. The line is expected to remain closed until at least 16:00 BST
- London Overground trains between Watford Junction and London Euston are experiencing severe delays
- A reduced overground service is running between Shepherds Bush and Clapham Junction
- It is not yet known whether the Caledonian Sleeper services on Friday evening will be affected
There is a regular shuttle service operating between Milton Keynes, Northampton and Wolverton. A separate shuttle train service between Euston and Harrow and Wealdston is being established.
A rail replacement bus service between Milton Keynes Central and Luton Airport Parkway is running for Virgin Trains customers.
Tickets for affected services are being accepted on: London Buses, Southeastern, Southern, Thameslink, East Coast, East Midlands, London Midland and TransPennine Express via any reasonable route.
Network Rail said: “Passengers wanting to travel on the West Coast main line and West London line are urged to check with their train operator or nationalrail.co.uk before travelling as disruption and cancellations are to be expected throughout the day.”
Nearly 60 firefighters were called to the blaze in Chantry Place, Harrow, at 23:47 BST on Thursday.
London Fire Brigade said a cordon was put in place at the warehouse fire and 12 local residents were evacuated amid fears that propane cylinders might explode.
The cause of the fire is not yet known.