The trial of two mountain guides charged with involuntary manslaughter over the death of six army recruits is underway in the eastern city of Chur.
On July 12, 2007, the guides gave the go-ahead for the group of soldiers they were leading to ascend the Jungfrau mountain despite a high risk of avalanche.
The defendants face up to three years in prison if found guilty by the military tribunal.
The six fell 1,000 metres down the flanks of the Jungfrau, a 4,158-metre peak in the Bernese Alps, and were carried away by an avalanche the group is said to have triggered itself. Six soldiers and the two guides escaped unharmed.
The guides are charged with failing to call off the attempted ascent. "Breaking off the tour would have been the right decision, given the steepness of the terrain, the risk of falling and the amount of new snow that had collected on the slopes," the prosecutor argued.
Between 55 and 75 centimetres of snow fell in the mountain region in the four days before the accident.
However, the guides defended their decision at the time, saying the weather was good on the day in question, and that it had stopped snowing. They added that no one was ordered to do the climb, with all agreeing to take part.
A verdict is expected by the end of the week.
Meanwhile, the judges rejected a request from the victims' families to file a civil suit against the guides.
According to military law, the judges said, only the government can be liable for damages.
Following the mountain tragedy and a river rafting accident a year later that took the lives of five soldiers, there was criticism that the army was not doing enough to minimise risks.
swissinfo.ch and agencies