Grenoble, France - A French teacher faces a manslaughter investigation after he led a group of students onto a closed skiing piste in the French Alps where an avalanche killed two of them as well as a Ukrainian tourist, a prosecutor said Thursday.
The teacher cannot be taken into custody "for the time being" because he was seriously injured in Wednesday's accident and is in hospital in the south-central city of Grenoble, prosecutor Jean-Yves Coquillat told a news conference.
A 16-year-old girl died on the spot while a 14-year-old boy died later in hospital.
The 57-year-old Ukrainian man who was killed was not part of the school group.
"The investigation should determine the psychiatric state of the teacher and his ability to lead a group," Coquillat said.
He said the piste was "closed with the usual netting with warnings in several languages - four languages," and that the group climbed over the netting "fully aware" of what they were doing.
The Bellecombes piste of the Deux Alpes ski resort, at an altitude of some 2,500 metres (7,000 feet), is rated a black piste - France's highest difficulty rating.
It had been closed all season because of a lack of snow. But heavy snowfall in recent days has blanketed the mountains, prompting authorities to warn of a high risk of avalanches across the French Alps.
The risk level on Wednesday at the resort was three on a scale of five - meaning a single skier can set off a snowslide, said Dominique Letang, director of the National Agency for the Study of Snow and Avalanches (ANENA).
"In 90 per cent of cases, it's the action of a human being that causes an avalanche," Letang said, noting that when the risk stands at five, skiing areas are closed.
He described the avalanche as "a typical case of a slab of snow formed by the heavy winds in recent days. Fresh snow did not attach enough" to the older layer, he said.
Letang added that the group should have been "properly equipped" with a probe, a shovel and an avalanche transceiver for finding people or equipment buried under snow.
The skiing season got off to a slow start in France as unseasonably warm temperatures left slopes bare over the festive season, with skiers and snowboarders having to make do with artificial snow until the recent snowfall.
Local mayor Stephane Sauvebois said "foolhardy risks were taken" when the group ventured onto the closed piste.
Outside the students' school in Lyon, some 110 kilometres (70 miles) from the site of the disaster, dozens of candles were lit alongside notes such as: "Thoughts with the students and pupils" and "Thoughts with the families, stay strong." Students at the school were incredulous over the tragedy.
"We're still in shock," said one who gave his name as Alain. "This outing takes place several times a year, with the same instructors, and there have never been any problems." Education Minister Najat Vallaud-Belkacem visited the school late Wednesday and said a grief counselling centre would be available there for "as long as needed".
Four other people have died since January in avalanches in the French Alps - two Lithuanian mountain climbers and two skiers from Spain and the Czech Republic.
Dozens die each year in avalanches in France's popular ski resorts. At least 45 people died in snowslides during the 2014-15 winter season in France, according to ANENA, more than double the previous year.
The deadliest avalanche in France's history occurred in 1970 when 39 people were killed when their chalet was hit by an avalanche at the Val d'Isere ski resort.