Two who were in a very serious condition were flown by helicopter to a hospital in Innsbruck in Austria. The nine others were taken to regional hospitals.
According to Rainews24, the driver was a 28-year-old man who lived locally and who "may have had a high level of alcohol in his blood".
He was arrested and put in hospital under police guard.

Some 160 emergency workers were at the scene, and a field hospital was set up by the roadside to provide first aid.
"A terrible scene, people on the ground, cries and pain, a tragedy - we don't have the words," a hotel receptionist told the Corriere della Sera newspaper.
"We have asked several times for a radar on this road as drivers speed up as soon as they leave Lutago, and here, one kilometre from the centre, they go at 100 kilometres an hour."
"The New Year has begun with a tragedy," South Tyrol governor Arno Kompatscher told reporters.
South Tyrol is a largely German-speaking province with a high degree of autonomy.
The German foreign ministry in Berlin said its consulate in Milan was "in close touch with the Italian authorities who are proceeding with the identification of the victims, assisting those who have been affected."
Lutago, located at an altitude of 970 metres (3,200 feet) in the picturesque Aurina valley, is popular with tourists who use the ski slopes of Klausberg and Speikboden.
The village of about 800 residents is the location for a popular Italian television series "A un passo del ciel" ("One step from heaven").
Last week, three Germans - a woman and two girls, one of them aged seven - were killed in an avalanche in South Tyrol.