Investigations
Three separate investigations were conducted. The first was a French judicial inquiry into the cause of the fire, the second was an internal inquiry by Eurotunnel and the third was an inquiry by the Channel Tunnel Safety Authority (CTSA), a bi-national body formed of personnel from British and French railway safety bodies, fire brigades and government departments.
The usage of the HGV shuttles had been approved with the plan, in event of fire, to continue to the terminal or to detach locomotive and coach. These had both failed, as the fire had damaged the train so it was forced to stop and that the overhead line had failed four seconds after the train had come to a stand. The concept of an 'unconfirmed alarm' meant that the incident was not treated seriously until five minutes after the train entered the tunnel on fire. The CTSA report recommended that all alarms be treated seriously.
The French crossover doors and one of the piston relief duct door failed to close properly allowing to smoke to enter the other running tunnel. Also, control centre staff were overwhelmed, having not been sufficiently trained for an emergency and using procedures and systems that were complex, meaning, for example, the supplementary ventilation system was late being switched on and ran incorrectly for fifteen minutes.
Read more about this topic: 1996 Channel Tunnel Fire