By The Associated Press

It could be weeks before officials at Tucson's Reid Park Zoo know what caused the death of the 17-year-old polar bear named "Snow."

The zoo says Snow was discovered Monday morning by her zookeeper. She was in her normal sleeping position with no signs of trauma.

Pathologists will conduct a full necropsy. Early results may be available by Thursday, but final results could take several weeks.

Zoo Veterinarian Alexis Moreno says Snow had a number of health issues but there were no immediate concerns. She says the polar bear had been swimming and eating well the day before and that her condition had improved since first arriving at the zoo in February.

The zoo has many geriatric animals in its care, but officials say Snow's death was unexpected.