A spokesman for First Capital Connect said: It has been a very difficult and trying time for our customers and we share their frustration. We would to offer our sincere apologies for the considerable disruption weve experienced. Services between Huntingdon, St Neots and London Kings Cross returned to normal service this morning (Wednesday). Network Rails managing director Robin Gisby said: I would like to apologise for the disruption passengers have experienced. We have had teams on site in Hitchin since Monday afternoon and working through the night to fix the problem, which originally occurred at 2.30pm on the Monday. Unfortunately, further damage was found nearby when services resumed this morning.