Tignes, France – The opening weekend of the ski season in Tignes was marred by a large avalanche on Sunday that swept down onto a marked ski run.

While details are still sketchy, early reports from local police indicate that up to four people on the Grand Motte Glacier were caught up by the slide, but were dug out by 70 rescuers equipped with beacons, probes and avalanche rescue dogs. The debris pile is said to have stacked up to three meters deep.

Strong southerly winds and 40 cm of heavy snowfall preceded the avalanche at midday on Sunday, and speculation is that off-piste skiers triggered the 300 meter wide, 400 meter long event above the Grande Motte cable car.

Tignes opened its 2013-14 ski and snowboard season only a day earlier on Saturday.