A concrete wall initially hampered rescue efforts to reach the crash site
By Matt Cole
BBC News, Halle, Belgium
Two stricken trains rest on snow-covered lines, their front ends raised up on the track and crumpled into one another.
The first few carriages of each of the commuter carriages also bear damage from the crash near Halle, Belgium, their lengths twisted, torn and buckled.
From a bridge overlooking the crash site, it can be seen how the trains came together, just a few hundred metres beyond a set of signals.
One train had clearly just begun crossing between different tracks when the head-on collision happened.
Alongside the crash site runs a high concrete wall, which in the early stages of the rescue operation hampered efforts to reach the carriages.
The 2.5m (8ft) wall is there to keep the public safe and away from the lines, but in this instance it also delayed emergency services, forcing them to walk several hundred metres round to get to the site.
Medical care was provided at a nearby sports hall
Once they had reached the crashed trains, rescue workers in red and yellow florescent vests spent four hours carefully picking through the wreckage trying to free those trapped inside.
The task was made more difficult by the dreadful weather conditions - not only were there freezing temperatures but snow blizzards too.
As word spread about what is believed to be Belgium's worst railway crash in 30 years, crowds of onlookers began to gather.
Among them were small children, being raised aloft by their parents to stare at the scene on the first day of their half-term holiday.
The walking wounded were taken from the crash site and up a hill to a nearby sports centre, where they received basic medical care.
Outside people with sombre faces hugged each other as all around the numbers of emergency personnel grew.
By mid-afternoon it became clear that at least 12 people had died but with growing concerns for further casualties, it was feared the figure would rise.
It's thought 150 people have lesser injuries, but even those without physical scars were offered treatment to help them deal with the psychological trauma of what they had been through.