Murdered.

Nothing is known for certain about Mr. Wolfinger except that he was from Germany. In October 1846, as the Donner Party was traveling along the Truckee, he stopped to cache his wagon. Augustus Spitzer and Joseph Reinhardt stayed behind to help, but returned without him. They reported that Indians had come down out of the hills and killed their companion, but Reinhardt later confessed to having murdered him.

http://user.xmission.com/~octa/DonnerParty/Wolfinger.htm