Horse that participated in the filming of the series “The Lord Of The Rings: The Rings Of Power” suffered a cardiac arrest during a rehearsal for a fight scene.

“The incident happened while the horse was getting ready for rehearsals. At the time, a veterinarian and a member of the American Humane Association’s animal welfare team were present. An autopsy confirmed the horse died of heart failure,” said a spokesperson for Amazon Studios.

According to sources, more than 30 horses participated that day for the needs of the series. The British “The Devil’s Horsemen” have been training horses for films and television series for 50 years. According to the company’s website, trained horses have appeared in the productions of ‘Wonder Woman’, ‘Justice League’, ‘Game Of Thrones’ and ‘The Crown’. This is the first fatal accident with a horse known by this company.

The animal was standing with about 20 others when it went into cardiac arrest. Other horses had begun to rehearse. According to the Daily Mail, the horses were being prepared for a battle scene.

Although horse deaths on set, as Deadline reports, are rare, they have sparked a backlash, with animal rights groups pushing for the use of visual effects.