"Luck" has ceased all future production, following news that a third horse died while filming the series, HBO said Wednesday.
The show's executive producers, David Milch and Michael Mann, made a joint decision with HBO to stop production.
“The two of us loved this series, loved the cast, crew and writers," Milch and Mann said. "This has been a tremendous collaboration and one that we plan to continue in the future.”
HBO said in its statement that it was "immensely proud of this series, and that it had striven to maintain high safety standards.
"Safety is always of paramount concern," HBO said. "We maintained the highest safety standards throughout production, higher in fact than any protocols existing in horseracing anywhere with many fewer incidents than occur in racing or than befall horses normally in barns at night or pastures."
Nonetheless, HBO said, "accidents unfortunately happen and it is impossible to guarantee they won’t in the future. Accordingly, we have reached this difficult decision."
The series -- which co-starred Dustin Hoffman and Nick Nolte -- had been renewed for a second season in January. "Luck" was Milch's third series for HBO, following "Deadwood" and "John From Cincinnati."
The most recent -- and third -- horse death related to the series occurred Tuesday at the Santa Anita Park race track in Arcadia, Calif., where the show was filmed. The horse reared up, fell backward and struck its head, requiring it to be euthanized.
The other accidents occurred during the filming of the pilot and the seventh episode. In those instances, the American Humane Association -- which worked with HBO on the production of the series -- said that the horses "stumbled and fell during short racing sequences." The animals were euthanized after severe, inoperable fractures were found by veterinarians on the set.
The deaths made "Luck" -- which premiered in January -- a target of the People for the Ethical Treatment of Animals, which called for law enforcement in Los Angeles to investigate the deaths. The organization accused the show of racing retired horses that were unfit for the work, and overworking them by racing them twice in the same day.
PETA claimed to have reached out to Milch and others associated with the show prior to the show going into production, but said that its efforts were "rebuffed."
"Perhaps if producers had considered the proved safety protocols that we would have suggested, these horses would still be alive," the organization suggested in a blog post on its Web site in January.