DULUTH, Minn. — The University of Minnesota Duluth student recovering from severe frostbite has undergone another amputation surgery.

Alyssa Lommel's mother, Teri, posted on her daughter's CaringBridge website that doctors were unable to save any of her fingers or thumbs. WDIO-TV (http://bit.ly/1exJqhS ) reports Lommel's mother says surgeons found more tissue damage than expected and had to amputate just below the knuckles of both hands.

The 19-year-old woman suffered severe frostbite and hypothermia after a night outdoors in Duluth when temperatures dropped to minus-17. Police say the sophomore from St. Cloud had been out drinking with friends, was dropped off, but never made it inside.

Lommel earlier had some tips on her toes removed, as well as part of one foot. Her mother writes that her daughter should be able to walk normally.