Damage to overhead lines at Luton is causing major disruption
Trains in the Luton area were brought to a standstill after overhead power lines were damaged.
Commuters using Thameslink and East Midlands Services were worst hit, with warnings of delays of up to 90 minutes.
A spokesman at Network Rail said a piece of cable came into contact with overhead electric lines at Luton station, causing them to suspend connections.
Links to Gatwick Airport were also affected. The company apologised.
Stranded passengers took to social media, with one commuter in St Albans claiming crowds were "milling around clueless".
The main services affected were East Midlands trains between Corby, Nottingham, Sheffield and London St Pancras.
Thameslink trains between Bedford, Luton and Three Bridges, Sutton, Sevenoaks and Gatwick Airport were also hit.
A replacement bus was running between Kettering and Corby as well as between Wellingborough and Northampton.
Network Rail said travellers could use their Thameslink tickets to get home on connected rail and underground services.
Apology
Earlier, a Network Rail spokesman said: "Due to a piece of cable coming into contact with the overhead electric lines at Luton station we are currently unable to run trains through the area.
"We are working to repair the problem and get trains running again as soon as possible with Network Rail teams currently on site.
"We apologise for any inconvenience this may cause and advise that passengers travelling through Luton this evening check with their train operator before they travel."
The disruption was expected to continue until the end of service on Tuesday.
