National Oceanic and Atmospheric Administration marine mammal response coordinator David Schofield said Monday the male Blainville's beaked whale was very sick.
A necropsy performed after the animal's death Sunday showed it had moderate pneumonia, a severe gastrointestinal problem, and kidney disease.
Beaked whales have been known to be more vulnerable to the harmful effects of Navy sonar than other whales. But Schofield says there's no sign this animal was affected by sonar.
The whale was taken to the Hawaii Cetacean Rehabilitation Facility in Hilo, Hawaii, on Aug. 16 after it was found stranded in Maui.