Lioness
A lioness killed the father of her cubs in an "unprovoked" attack. In this image: A lioness with a radio collar roars in the evening light Ngamiland district Maun, Botswana, June 10, 2010. Getty Images/Chris Jackson

Indianapolis Zoo authorities Friday said a lioness has fatally attacked a lion who fathered her three cubs, multiple reports said.

Zoo officials said they heard a commotion early morning before the zoo opened to the public on Oct. 15. They saw the lioness Zuri attacking Nyack, while one of their cubs stood nearby. Zuri held on to Nyack by the neck. Though the officials attempted to separate the two, they were unable to do so. Zuri finally released her hold when Nyack stopped moving, a report in FOX 32 said.

The zoo announced the death of the lion in a Facebook post which read, “Our Zoo family is sad to announce that 10-yr-old male African lion Nyack has died. Earlier this week he was injured during a physical incident with female lion Zuri. We will conduct a thorough review to attempt to understand what may have led to this. Zuri and the other three lions are all ok. Zuri and Nyack had three cubs together three years ago. Nyack was a magnificent lion and he will be greatly missed. We appreciate the support from our community as we cope with the loss.”

“We don’t know what the precursor to the fight was,” David Hagen, the zoo curator, said. “They had been together for eight years and during that time they had done really well together.”

Hagen said the workers at the zoo were upset.

"The staff is devastated by the loss," Hagen said. "He was a friendly, playful lion and he will be greatly missed." According to a report in Fox News, Nyack will be cremated.

A necropsy of the animal said the cause of death was suffocation. A thorough review will be conducted by the authorities to attempt to understand the situations behind what might have prompted the lioness to kill the lion.

According to a report on FOX 32, Zuri and Nyack were compatible from the time the lion, who was 10 years old, arrived at the zoo on loan from the San Diego Zoo. There were no reports of aggression during the eight years the two were kept together. They became parents to three cubs three years ago, it added.

"The attack that occurred took everyone by surprise; it surprised me," Craig Packer, professor and director of the Lion Research Center in the College of Biological Sciences at the University of Minnesota, said. "I've never heard of a female attacking a male."

"Extreme aggression of females to males is definitely unique," Packer told IndyStar.

"They called me because they were puzzled, and I agree it's puzzling," Packer added. "It [the attack] was completely unprovoked and it was certainly not typical."

Zuri and the three cubs will continue to be part of the exhibit, reports said.