The court documents say assistant director Dave Halls, who had handed one of three prop weapons to Baldwin that were set up in a cart by an armorer, did not know the prop gun contained live ammunition and indicated it was unloaded by yelling "cold gun!".

According to an affidavit for a search warrant for the movie set at Bonanza Creek Ranch in northern New Mexico filed by the Santa Fe County Sheriff's Office, the "cold gun" remark was meant to indicate or confirm that the prop weapon did not have live rounds.

Aerial view of 'Rust' set in New Mexico where the fatal shooting occurred. Screengrab from YouTube.

But when the senior actor fired the gun, a live round hit director of photography Hutchins, 42, in her chest and wounded film director Souza, 48, who was nearby, the affidavit said.

Halyna Hutchins was airlifted to a hospital where she was pronounced dead, while Joel Souza was admitted to another medical facility with 'non-life threatening' injury, according to the affidavit.

Los Angeles Times and other local media reported before Thursday's fatal shooting, some crew members of the movie quit the production over concerns related to safety, including gun inspections and Covid-19 protocols not being followed properly.

The film's production company, Rust Movie Productions LLC, in a statement said production of the film has been halted for an undetermined period of time following the accident.

"We are fully cooperating with the Santa Fe Police Department's investigation, and we will be providing counselling services to everyone connected to the film as we work to process this awful event," the statement read.

According to a report by Deadline, an internal investigation into the tragic incident as well as a 'safety review' have been initiated.

Besides saying that he is fully cooperating with the investigation into 'Rust' movie set tragedy, Baldwin said on Twitter that he was heartbroken after the incident claimed the life of the cinematographer.

"There are no words to convey my shock and sadness regarding the tragic accident that took the life of Halyna Hutchins, a wife, mother and deeply admired colleague of ours," Baldwin tweeted.

"I'm fully cooperating with the police investigation to address how this tragedy occurred and I am in touch with her husband, offering my support to him and his family," his tweet added. "My heart is broken for her husband, their son, and all who knew and loved Halyna."
  
CNN affiliate KOAT Action 7 News reported quoting Benjamin Herrmann, a lawyer at Herrmann and Sumrall P.C. law firm in New Mexico's Clovis, that Alec Baldwin was unlikely to face charges if the actor was oblivious that the prop weapon had live ammunition in it.

This is not the first deadly accident caused by a prop gun in a movie set. Martial-arts legend Bruce Lee's son, actor Brandon Lee, was killed at age 28 in a prop weapon shooting accident while filming the movie, "The Crow" in 1993.

Brandon Lee in "The Crow" movie. Image credit: Twitter/Brandon Lee's family

Condoling Halyna's death with prop gunshot, Brandon Lee's family tweeted: "Our hearts go out to the family of Halyna Hutchins and to Joel Souza and all involved in the incident on 'Rust'. No one should ever be killed by a gun on a film set. Period. Broken heart."

In an almost similar incident, actor Jon-Erik Hexum died on the set of "Cover Up: Golden Opportunity" in 1984 after he put a gun to his head and pulled its trigger while playing with the weapon on the movie set.