Phoenix Zoo lost one of their beloved apes Saturday morning.
According to the zoo, 30-year-old siamang Frances was found dead in the water surrounding her island habitat after zookeepers didn't immediately see her during their checks.
Frances had been at Phoenix Zoo for seven years and had recently been housed with another siamang at the animal clinic at the zoo while their habitat was being renovated, the zoo says.
She had been returned to the habitat Thursday, but the male stayed at the clinic for health reasons.
The zoo is waiting for a necropsy to determine her cause of death.
Siamangs, black-furred gibbons in the lesser ape family, are native to Malaysia, Thailand and Sumatra.
The zoo says they are known for their loud calls.
The siamangs at Phoenix Zoo are located on the Children's Zoo Trail on an island surrounded by water. The animals reportedly don't cross the water, so it was unusual for the deceased siamang to be found there.