A location manager for “Rust” says at least four people were responsible for checking the weapon that killed cinematographer Halyna Hutchins — including gun-firing star Alec Baldwin.

“A massive mistake was made,” Stacey Mickey-Evans told Australia’s 92.5 Triple M Gold Coast.

“There are massive protocols to stop these things from happening. There are multiple checks for it,” she said Sunday.

She noted that the armorist, assistant director and the key grip are supposed to “check the gun … no matter what’s going on on set.

“And then very lastly, the actor checks the gun,” she said of Baldwin, who was also one of the movie’s executive producers.

“So there are four to five people in this stage,” she said, but “somehow there was a failure.”

Mickey-Evans said she finds it “difficult to talk” about the “terrifying” tragedy in which Baldwin killed Hutchins, 42, and injured 48-year-old director Joel Souza on Thursday.

The shooting left blood splattered over the Hollywood star, who changed out of the Western outfit he was wearing and into street clothing before talking to investigators, law enforcement documents released Sunday showed. His clothes were taken by investigators as evidence.

“This was obviously a real weapon, and this particular weapon was supposed to be loaded with blanks,” the location manager told the Australian station’s podcast.

“That is what everyone thought, that it was checked and double-checked and triple-checked … supposedly.

“That obviously didn’t happen,” she said.

“Somewhere along the lines, it fell through the cracks,” she said.

A search warrant released Sunday says Assistant director Dave Halls “grabbed one of three ‘prop-guns’ that was set up by the armorer” Hannah Gutierrez Reed on a cart left outside the makeshift structure where filming was being done.

“The cart is a gray in color rolling table with two layers and was left outside of the structure due to COVID19 restrictions,” the warrant says.

Halls “handed the gun to the actor Alec Baldwin” and yelled, ‘Cold gun,’ indicating the prop-gun did not have any live rounds,” the document says.

“The prop-gun was fired” by Baldwin, the document said — without any mention of anyone making safety checks on the weapon.

After the deadly shooting, Baldwin gave the gun back to Gutierrez Reed, who took out the spent casing and then gave the weapon to deputies when they arrived, the documents show. 

Baldwin then changed into “‘street clothes’ prior to leaving the scene,” with his old Western costume handed over with apparent blood stains, the search warrant says.

Mickey-Evans noted how Gutierrez Reed — a 24-year-old former model in charge of weapons for only her second time — was “very young.

“Does that mean that she was the one that messed up? Not necessarily,” Mickey-Evans insisted, ticking off the list of other people including Baldwin who should have checked the gun.

But either way, what happened “is a huge mistake and tragic,” the location manager said.

Mickey-Evans noted how just “most of the movie crew … almost went on strike” because of the “unsafe work conditions” on the set in New Mexico.

She also joined calls for real guns to be banned from TV and movie sets.

“Listen, we have [computer-generated imagery], we have green screen — we can do all of these things these days,” she said.

“Why do we actually have to have a weapon that is loaded on a set with all of these people around?

“We do a lot of dangerous stuff every single day — we blow things up, we land helicopters in the middle of roads, we do all kinds of stuff — but this is something that’s unnecessary,” she said of using real guns as props.

“Let’s have fake weapons, rubber weapons and use CGI.”