US film director pleads guilty after train crash kills camera assistant and injures six workers

The director of a movie about musician Gregg Allman has been sentenced to two years in jail after pleading guilty to involuntary manslaughter following the death of one of his camera assistants.

Midnight Runner director Randall Miller, who was also charged with criminal trespassing, was ordered by a US court to pay a $US20,000 ($A25,950) fine as part of a last-minute plea deal.

In addition to two years behind bars, Miller agreed to serve an additional eight years on probation as part of the deal which saw Georgia prosecutors drop charges against his wife and business partner, Jody Savin.

The executive producer of the film, Jay Sedrish, also pleaded guilty and was handed 10 years on probation.

All three were facing charges relating to the 2014 death of camera assistant Sarah Jones, who died when a freight train travelling 89km/h hit the director's crew on a Georgia railroad bridge. Six other crew members were also injured in the incident.

Prosecutors said all three defendants knew that permission to film on the tracks had been denied to them, but they proceeded anyway 

The death of Jones galvanised behind-the-scenes film workers nationwide to push for improved safety standards on sets.

Her father told reporters outside court that he hoped her death wasn't in vain.

"We hope the sacrifice of our daughter's life will continue to change the film industry," Richard Jones said.

"I  believe it sends a message, frankly, that if you do not respect those you're in charge of, you may end up behind bars."

The case is a rare example of filmmakers being prosecuted for deaths that occur on their sets.

Under state law, someone can be convicted of involuntary manslaughter for committing a misdemeanour - in this case trespassing - that unintentionally causes another person to be killed.

Miller's lawyer, Ed Garland, who expects his client to be released from jail within 12 months, says he never intended to put his workers at risk.

"Randall Miller at the time this happened believed there were not any more trains that would come down that track," Mr Garland said.

"But he accepts responsibility."

Actor William Hurt was on the set in his role as the Allman Brothers Band singer in his later years when the tragedy happened.

A metal-framed bed was pulled across the tracks as a prop, but when the train struck, it smashed the bed and hurled metal fragments at the fleeing crew.

The train struck and killed Jones, a young camera assistant from Atlanta who had worked on TV series including Army Wives and The Vampire Diaries.

The movie has been put on hold ever since, with Allman securing an out-of-court settlement with Miller last year, which prevents the director from reviving the film.