A passenger caught up in the devastating train crash that killed a driver and left at least 33 people seriously injured said the impact sounded 'like a terrorist bomb exploding' as people were thrown from their seats. Passengers suffered broken bones and were left 'spitting out blood' when a Luton Airport Express service ploughed into the back of a stationary East Midlands Railway train at around 5.15pm on Friday. A video taken inside one of the carriages shows panicked travellers lying on the floor and crying out for help. One person can be heard frantically saying 'we need to get off'. Eyewitness, Dr Pete Knapp, 40, who was travelling in the front carriage of one of the trains, said his first thought was that a 'terrorist bomb' had gone off. 'There was a moment of being flung into the chair in front, and then I saw smoke. People were crying, screaming, people were so scared and confused,' he said.'I got up and I saw a lot of people who were unable to speak, had broken legs, and then I managed to get out of the train and because I'm quite thin I was able to squeeze out through the gap in the doors.' He added that some people were 'spitting out blood'. Investigators are examining whether a fault with the stationary train's safety systems may have played a role in the crash. The 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 East Midlands Railway service, while its driver was reporting the issue to maintenance staff by phone. A video taken inside one of the carriages after the crash shows panicked travellers lying on the floor and crying out for help A Luton Airport Express train crashed into a stationary train causing serious injuries and bloodied passengers on board Aerial image shows the aftermath of the train crash in Bedford yesterday afternoon Passengers were left with 'bloodied faces and broken legs' following the crash Injured passengers gather by the side of the tracks after two trains collided near Bedford last night The collision involved the 3.50pm service from Nottingham to St Pancras International and the 4.40pm Corby to the major London station. According to the East of England Ambulance Service, 11 people suffered very serious injuries, 22 had serious injuries and 56 were left with minor injuries. A passenger on one of the trains said he thought 90 per cent of people on his carriage had serious injuries, could not stand or move their neck.Speaking to BBC Radio 4's Today programme, Brett Byatt said: 'The people in first class ended up with stomach and rib injuries, because they went into the tables they have in first class, and EMR (East Midlands Railway) trains, the way that they're structured with seats, was probably the worst way it could have been structured for a train crash, in the sense that there's nothing… because they're, they face each other in the three by three and the two by three, and the seat… when people flew into one another, the seats that they were on, like, broke backwards into the people behind them.'The teacher, who lives in Bedford and was unharmed in the crash, added: 'I've said before that I'd probably say 90 per cent of the people on my carriage had injuries, I'd probably say from three to four of us were uninjured in a full carriage.'Everyone else had either a serious wound that was bleeding profusely, or a situation where they couldn't stand, or couldn't move their neck, or I saw a woman's snapped leg.'Eddie Dempsey, the general secretary of the National Union of Rail, Maritime and Transport Workers confirmed last night that the person who had died was a train driver. He said in a statement: 'We are devastated to learn that a train driver and former RMT rep has tragically died as a result of today's crash between Luton and Bedford. 'The thoughts of RMT are with their family, friends, colleagues and the ASLEF trade union at this awful time.' Picture from today shows one of the trains that was involved in the collision yesterday afternoon Dozens of emergency services were at the scene The train going to Corby collided into the back of the Nottingham train