This picture, taken by passenger Martin Stewart, shows the broken cable hanging over the track in Radlett station yesterday.
Severe delays have been predicted on Southeastern, East Midlands Trains and First Capital Connect until the end of the week.
More top news
The property developer painted the mews house in March last year after she was denied permission for a basement below the property.
Profits at the estate agent plummeted 42% in the first half of the year.
Ionut Gheorghe, 27, was detained in Los Molinos near Madrid on Friday by Spanish police under a European Arrest Warrant.