African elephant who lived at Oakland Zoo for decades has died

African elephants Lisa (left) and Donna greet each other at the Oakland Zoo in Oakland, Calif. on Wednesday, Dec. 31, 2014. The zoo has long opposed the use of bullhooks to manage its elephants in favor of a protected contact, large barricade system …

A beloved African elephant who spent decades at the Oakland Zoo has died.

The Oakland Zoo announced Friday that Donna the African elephant died suddenly at the elephant sanctuary in Tennessee.

Zoo officials say on Tuesday, sanctuary staff noticed a difference in her demeanor, and while under observation, Donna died.

The 44-year-old elephant lived at the Oakland Zoo from 1990, until last year, when she was moved to the Tennessee sanctuary after her companion died.