HBO's 'Luck' Another Horse Dies on Set

3/14/2012 2:00 AM PDT

Another Horse Dies On HBO's 'Luck' Set

There has been another fatal horse accident on the set of the HBO series "Luck" -- a third horse has died, TMZ has learned.

We're told the crew was trying to get a horse out of its stable when it reared and fell back, suffering a head injury.  The horse was euthanized at the Santa Anita Race Track in Arcadia.

This is the third time a horse had to be euthanized during the filming of the series, starring Dustin Hoffman.

HBO was scrambling after TMZ called 2 hours ago with the story, and the publicist, Karen Jones, stalled us while they got their story together.  In fact, when we told her about our story, she said it wasn't all true -- but it was.