(KABC) -- Big Bear's beloved bald eagle Jackie died from complications related to a type of infectious avian flu, according to necropsy results.

The California Department of Fish and Wildlife, San Diego Zoo Wildlife Alliance and Ojai Raptor Center on Wednesday released the results of testing conducted after Jackie's death, shedding new light on the illness that veterinarians had been trying to diagnose during weeks of treatment.

The findings determined that highly pathogenic avian influenza, or bird flu, was the primary underlying cause of Jackie's decline.