Services to King's Cross station are now running a day and a half after problems with power lines in Hertfordshire brought cancellations and chaos to passengers across East Anglia.
No trains were running through Peterborough and Hitchin and some passengers were even forced to get out and walk back to stations along the track.
There are still some delays but the rail operator Network Rail says a normal service should be running by this evening.
Travellers travelling to and from London on the East Coast Main Line are experiencing delays and disruption to services following problems with overhead power lines.
Services between King's Cross and Peterborough have begun again after thousands of commuters suffered delays caused by overhead power line problems.
Rail services on the East Coast Main Line are expected to resume again after faults with overhead power lines caused major disruption.
There's not such good news for people wanting to travel between Welwyn Garden City and Letchworth as trains there are due to be disrupted for the rest of the day.
Services between Cambridge and King's Cross are also expected to be disrupted for the rest of the day.
It's not yet known what caused a series of problems with overhead power lines.
Thousands of rail commuters are facing delays and cancellations after overhead power line problems on the East Coast Main Line.
Rail commuters endured more travel misery this morning on one of the country's busiest lines.
Engineers say the problem involves 14 "droppers" which are part of the overhead wires and which were found to be broken and causing damage to trains.
Rail services on the East Coast Main Line have been severely disrupted by problems with overhead power lines.
East Coast, Grand Central and First Hull Trains are starting and terminating at Peterborough, meaning they are unable to run between Peterborough and King's Cross.
First Capital Connect are running shuttle train services between Letchworth Garden City and Cambridge, between Biggleswade and Peterborough and between Welwyn Garden City and King's Cross.
Buses are replacing trains between Letchworth Garden City and Welwyn Garden City and between Letchworth Garden City and Biggleswade.
Trains between Stevenage and Luton and between Stevenage and Hertford North are also being replaced with trains.