The accident happened on a service transporting passengers from the resort town of Stresa up the nearby Mottarone mountain in the region of Piedmont.
Images from the scene show the wreckage lying in a steep wooded area.
Officials said two survivors, aged five and nine, were taken by helicopter to a Turin hospital.
Alpine rescue officials confirmed in a Sunday evening tweet that the final tally of those involved was 13 dead and two injured, after the death toll steadily rose in the hours after the accident as the wreckage was searched.
