The death of a third horse turned out to be unlucky for HBO's racing series Luck. Producers have decided to cancel the show. Officials said "with heartbreak" that they're ceasing "all future production," reports the BBC. While we "maintained the highest safety standards possible, accidents unfortunately happen, and it is impossible to guarantee they won't in the future," said an HBO statement. "Accordingly, we have reached this difficult decision." Two horses were put down after suffering injuries in racing scenes during filming of the show's first season last year. A third was killed this week when the animal reared up and fell, striking its head, as it was being led back to its stall. The series examined the seedier side of racing, and featured Dustin Hoffman and Nick Nolte. (More HBO stories.)