The Grayrigg derailment in 2007, resulting in the tragic death of Mrs Masson, was a terrible event.
Within hours of the event it was clear that we were responsible, that the infrastructure was at fault, so it is right that we plead guilty.
We again apologise to Mrs Masson's family for the undoubted grief this has caused them.
Network Rail is facing an unlimited fine after its lawyers said they would plead guilty to health and safety breaches.
It's taken five years to prosecute Network rail after the train derailed near the Cumbrian village in February 2007