Southern has apologised to commuters after numerous train cancellations yesterday evening left hundreds stranded.
Crew sickness and train breakdowns saw major disruption to services leaving London terminals during evening peak time.
A Southern spokesman said a train at Clapham Junction had appeared to strike flood debris, causing a blockage on the line for most of the day.
Cancellations have continued today, the spokesman said, because of crew shortages and the railway bridge at Tulse Hill being struck by a vehicle.
He said: “We apologise to our passengers for the disruption to Southern services leaving London terminals last night. Some services were cancelled due to train crew non-availability and the knock-on effects of an incident where a train sudden lost power at Clapham Junction earlier, causing widespread disruption as one line was blocked.
“Because of this, some trains and train crew were out of position for the evening peak which led to further cancellations.
“Passengers who were delayed by 30 minutes or more can claim compensation on our website at www.southernrailway.com/delayrepay.”
One commuter described ‘disgraceful and dangerous’ conditions at London Victoria, with delayed commuters attempting to cram onto a train at around 6pm.
Social media was flooded with complaints about the delays.
Clara Limpus said: “It’s taken me longer to go from Gatwick to Haywards Heath than it did Bordeaux to Gatwick. And I’m trying to get to Lewes.”
Others tweeted links to a petition to remove the franchise for Southern Rail from Govia Thameslink, while some complained the cancellations had led to them missing England’s 2-1 defeat to Iceland at Euro 2016.