Unanswered questions are mounting after a train crash that left one driver dead and nine people fighting for their lives in hospital in the worst rail disaster for 20 years. A total of 100 people were injured, 32 seriously, after a Luton Airport Express service running from Corby to St Pancras ploughed into the back of a Nottingham to St Pancras train at around 5.15pm on Friday.It makes it the worst railway crash in Britain since the derailment of a train at Grayrigg in Cumbria in 2007 - when one person was killed and 100 injured.Passengers suffered broken bones and were left 'spitting out blood' when the two East Midlands Railway trains collided, after the Nottingham service ground to a halt on the tracks due to a technical fault.Some travellers reported being 'flung' from their seats into the chairs and tables in front, before seeing the carriages fill with smoke – although the fire service has confirmed this was not the result of any blaze. A major incident was declared and more than 80 people received treatment in hospital last night, with 28 still in hospital on Saturday morning, Chief Constable Lucy D'Orsi of British Transport Police said. Brett Byatt, a teacher who was travelling on the Corby train which slammed into a stationary Nottingham carriage, said: 'I knew something was up because the train never slows down from Bedford to Luton - and I felt it brake.'Amid reports of a technical fault with the first train's automatic warning system (AWS), passengers have hit out at the UK's ageing railway network.The AWS system is designed to automatically apply the brakes if a driver fails to acknowledge an approaching red signal.It is understood the Luton Airport Express train collided with the other stationary EMR service while its driver was reporting the issue to maintenance staff by phone.Investigators and police remained at the scene, near Bedford, throughout Saturday as they began probing the possible cause of the crash. Investigators begin their work in the aftermath of the train crash near Bedford on Friday evening British Transport Police officers, Rail Accident Investigation Branch officers and Network Rail work at the site of the crash Passengers filmed the aftermath of the incident, which showed panicked travellers lying on the floor and crying out for help