French Alps avalanche
Teacher whose pupils were killed in an avalanche after straying onto a black run had previously received psychiatric treatment Getty/Stringer

The French school teacher whose pupils were killed during an avalanche on a closed "black run" piste in the Deux Alpes ski resort in the French Alps is to be investigated by authorities after it emerged that he had been discharged from a psychiatric unit two months ago. It is understood that the 47 year-old PE teacher, whose name has not been released, had been prescribed antidepressants and mood stabilisers following his release.

A 16-year-old girl died at the scene of the accident on a slope called Bellecombe on Wednesday (13 January) while a 14-year-old boy died later in hospital. A Ukrainian man who was not connected to the school group also died. At least two other members of the school group were found to be in a state of cardiac arrest and the teacher was discovered to have sustained multiple injuries.

The injured were transferred to a hospital in Grenoble, where the teacher is currently in police custody. The teacher has head injuries and a fractured elbow facing a manslaughter investigation, after reports said that he had already taken the children down the same black run the previous day.

The piste, which is measured at 2,500m (7,000ft), was rated "black" – the highest difficulty rating – and had been closed all season because of a lack of snow. It had, however, been subject to heavy snowfall at the time of the accident prompting authorities to put out an avalanche warning for the region. At the time of the incident the avalanche danger level had been set at three out of a possible five.

The dead children were pupils at Saint-Exupery school in Lyon, where people laid flowers and lit candles on the evening of the tragedy. The French authorities swarmed the piste on news of the accident with dozens of rescue workers joining the hunt for survivors. Three search dogs were brought in while three helicopters were dispatched to ferry victims to hospital.

In total, there were 19 pupils and three teachers on the school trip, but not all were on the closed black run piste at the time of the accident.