For anyone who was delayed by train services to Gatwick Airport or Brighton on Sunday this was caused by sinkholes.
Planned engineering work was taking place on a bridge just outside of Purley station when the holes were discovered.
Lines between Purley and East Croydon were immediately closed for the safety of passengers which also meant the Gatwick Express was suspended.
Network Rail apologised to customers who were impacted by the delays and said they were working as quickly as possible to safely open the railway.