Network Rail faces a multi-million-pound fine this week for its part in the Paddington train crash, Britain's worst rail accident for a generation.
Thirty-one people died when a Thames Trains cross-country service went through a red signal and hit a Great Western express outside the station in west London in October 1999. Hundreds of people were injured after fire engulfed some of the carriages.
Network Rail, which took over from Railtrack after the accident, pleaded guilty last year to breaking health and safety rules because of problems with being able to clearly see the signal, although the company denied responsibility for the crash.