A landslip caused by flooding from a burst water main caused rail chaos on busy commuter routes for a second day running today.
Many services were cancelled and buses replaced trains on some routes following the flooding close to South Croydon station in south-east London.
The train companies affected were Southern, Gatwick Express and First Capital Connect.
Trains were able to run on the Gatwick Express between Victoria station in London and Gatwick airport in West Sussex, but there was reduced frequency and extra stops.
A number of trains running from Brighton to Bedford were cancelled and South Croydon and Purley Oaks stations were shut all day.
Also axed were a number of Victoria to Brighton trains as well as some services between London Bridge and Reigate in Surrey, while buses replaced trains between Oxted and East Croydon.
Passengers travelling to Gatwick for flights were being advised to allow extra time to reach the airport.
Water poured down an embankment on to tracks after the main burst yesterday, bringing earth and debris down with it.
A Network Rail spokesman said today: "We have had teams working all night to clear thousands of tonnes of debris off the tracks and work is continuing.
"Full services will be restored as soon as possible."