Thousands of rail commuters from Brighton, Hove and Portslade face long delays on their way home this afternoon after a landslip blocked the main line.
The landslip, in the South Croydon area, was caused by a burst water main in Stanhope Road which was reported at about 9.30am today.
The track is covered in water and debris and no trains are running south from East Croydon.
All lines between East Croydon and neighbouring South Croydon Station are blocked.
Trains between Brighton and Gatwick are running once every half hour.
Anyone heading to the airport is advised to allow three to four hours for their journey.
Replacement buses are running but Southern, the train operator, said: “East Croydon station is extremely busy at the moment with very long queues waiting for replacement buses.”
Southern urged passengers not to try to travel home via Victoria but to use Waterloo and Charing Cross instead.
A trackside fire between Tonbridge and Hastings added to the disruption.
The company said that London Buses, Metrobus, London Underground, South West Trains, Southeastern, London Midland, First Great Western, Croydon Tramlink and First Capital Connect were accepting Southern tickets on any reasonable route.
First Capital Connect, which runs Thameslink services, said that the first train from London Bridge to Brighton would not be until after 7pm this evening.
The track will be closed again later this evening for emergency engineering works.