Accident is worst since King's Cross fire in 1987

London Underground may have remained mercifully free of accidents in recent years, but the 1975 Moorgate crash and the 1987 fire at King's Cross are scars on its 140-year history that remain to this day.

And it was revealed only last week that disaster was narrowly averted in 2001 when hundreds of passengers were trapped on three Tube trains for more than an hour on one of the hottest days of the year.

The deaths of 43 people at Moorgate occurred when the morning rush-hour train failed to stop and ran out of track. Hundreds more were injured. The crash was blamed on the 56-year-old driver of the train, who unaccountably sped into the station at 30mph, twice the limit.

By contrast, the King's Cross fire, in which 31 people died and 150 were injured, was an institutional catastrophe that cost £4.5m in damages and led to an overhaul of safety measures across the Tube network.

The fire began under an escalator, and turned into a fireball that devastated the ticket hall. Smoking was banned on the Underground, and fire doors and sprinklers installed.

A report into the summer 2001 incident, leaked last week, highlighted a catalogue of errors and found that if conditions had been "slightly different", the consequences "could have been disastrous". London Underground's director of safety, Mike Strzelecki, conceded that mistakes were made.

Century on the Central

The Central Line, which runs more than 50 route miles from West Ruislip and Ealing Broadway in the west to Epping and Hainault in the east, is one of London's oldest Tube lines. It opened in 1900 and was built and operated by a private company, the Central London Railway, though it was extended after the Second World War.

Unlike the modern Victoria or Jubilee lines, the old section, which goes through Chancery Lane, does not go in a straight line, but wends its way under central London around various curves.

Today, the line is one of the busiest. Modern trains, built in 1992, carry more than 1,000 passengers each, and run at intervals as short as three minutes during the peak hours.

The line was modernised with a new signalling system six years ago, which allows the trains to operate without drivers. But this has suffered problems, leading to delays and incidents in which hot and overcrowded trains have been stuck between stations.

Michael Williams