Richard George struggled to read a statement he had prepared at the inquiry investigating the Swansea to Paddington service, which collided with a freight train in west London on 19 September 1997.
Yesterday's hearing took evidence from former and serving GWR employees and station staff, many of whom said they were plagued by feelings of remorse and guilt, even when not culpable in any way.
Visibly distressed, Mr George said: "I was among passengers on the Southall train and as the managing director of Great Western Trains at the time I feel very acutely my full share of responsibility for the circumstances leading to the crash. There is not a day, not an hour that goes by that it is not in my thoughts."
The inquiry heard that Mr George had tried desperately to help fellow passengers in the aftermath of the accident.
He described the seconds before the impact, saying: "I recall a very loud `whoomph' and then some violent shocks. Having got out of my seat we were then up for a series of very violent shocks as we came into collision."
Mr George described his emotional state at the time as "distressed", adding: "Judging by the scale of the damage I knew there had to have been fatalities."
The hearing continues.
n The rail regulator promised yesterday that the United Kingdom's rail services were going to improve over the next five years. Tom Winsor said he was confident the change would take place and added that Railtrack in Scotland was leading the way.Reuse content