Soon after 2.30pm yesterday damage was found to overhead power cables on three lines around Hitchin. This damage was confined to the wire itself and not the structures, but was significant enough that we had to stop traffic through the area.
By 6.30pm we had two lines through Hitchin open allowing limited services to run. The route to Cambridge remained blocked, although passengers from London were and are able to reach the town via Liverpool Street.
From 1am to 5.30am we had just one line open through the affected area, with diversions via Hertford, while the damaged wire was replaced.
We handed the line back at 6.3am and when the first train went through at 6.54am, further damage was found.
The nature of the damage means we have had to close all lines through Hitchin and we are continuing to repair the problem and investigate the cause.
Network Rail would like to apologise for the disruption to people's journeys during this period and we are working hard to fix the problem.
Please do check with your train operator before travelling as there are diversions in place.
More top news
A man has died and two others have been injured in a stabbing outside Parsons Green Tube station.
Dany Cotton says referring to 'firemen' reinforces the stereotype that only men want to work in the fire service.
His heart completely stopped and one of his teammates performed CPR until paramedics arrived.