Poonam Bhattal was on a class trip to Claviere, Italy, about 50 miles west of Turin on the French border. She was on the chairlift but standing up before she fell, the lift operator said.
The metal safety bar was down and Bhattal could be seen grabbing onto it before she let go and plummeted to her death, the BBC reported Saturday.
Officials said they don't know why Bhattal stood up on the lift.
"Before she fell down she was grabbing for the safety bar and the men [operating] the lift saw this, stopped the lift ... but it was too late," said Marco Steffanini, a spokesman for Skibound, the group that organized the trip.