Poland train crash: 16 killed as trains collide 'after human error' A line where the accident occurred was closed due to engineering works, and one of the trains should have been moved onto a stretch of a third line to allow the train travelling in the opposite direction to pass. But this failed to happen. Head-on collisions between two trains are extremely rare and railway experts quoted by the Polish media said extensive procedures and systems exist to prevent them happening. Drivers have to get permission from the signal room to take a train onto a section of track in the wrong direction, and warning systems in the control room should have alerted signalmen to the possibility of a collision. Prosecutors said they had retrieved the data recording "black boxes" from the two locomotives, and are also expected to interview the two drivers, both of whom survived with light injuries. But many of the injured were in a critical condition with some in induced comas and others suffering from serious trauma wounds caused by the ferocity of the collision. "Passengers were sleeping then there was loud bang and a massive jolt that threw me onto the floor," said survivor Lukasz Kmita. When I got outside I found the two carriages at the front of the Warsaw-bound train had been torn apart. The locomotive had destroyed them. There was a lot of blood and screaming. Mr Komorowski declared national mourning, and praised the hundreds of fire fighters and police who battled through the night to rescue people from the twisted wreck of carriages. The crash is as a blow to Polish prestige coming just months before the start of the 2012 European football championship in June. Hundreds of thousands of football fans are expected to descend on the country, and rail will be a prime form of transport. Piotr Kazimierowski, president of Poland's Rail Transport Employers Forum, said a lack of money was contributing to a rise in the number of accidents on Poland's 20,000 kilometres of railways. "The number of accidents of has been increasing in recent years due to long-term under-investment," he told the Polish News Agency. "A lot of the older infrastructure is coming to the end of its life," he continued, although he added that rail travel on the whole remains extremely safe.