On the morning of October 21, 2021, which was to be the twelfth day of filming, seven unionized members of the film's camera crew collected their belongings at approximately 6:30 a.m. MT in a walkout.^[26] They claim they were told to leave the set, with a producer threatening to call the police, and were replaced.^[27][28] According to a statement given to TheWrap by an anonymous insider, several crew members took a number of prop guns off-set that day, including the firearm involved in the incident, to pass the time shooting at beer cans with live ammunition.^[29] After a lunch break, the prop guns had been returned.^[29] It is not clear if the firearms were checked again.^[30] On October 26, the Santa Fe County district attorney said these claims were still unconfirmed.^[31]

Later that day, the cast and crew were rehearsing a gunfight scene taking place inside of a church at the Bonanza Creek Ranch. Firearms and ammunition were retrieved from a locked safe and armorer Hannah Gutierrez-Reed placed three guns to be used in filming on a cart.^[26] Among them were a plastic gun that could not shoot live ammunition, a modified weapon that could not fire any type of ammunition, and a solid-frame .45 Colt revolver replica made by Pietta.^{[26][32][33][34]}

According to a search warrant, the guns were briefly checked by Gutierrez-Reed, before assistant director David Halls took the Pietta revolver from the prop cart and handed it to Baldwin.^[35][36] In a subsequent affidavit, Halls said the safety protocol regarding this firearm was such that Halls would open the loading gate of the revolver and rotate the cylinder to expose the chambers so he could inspect them himself. According to the affidavit, Halls said he did not check all cylinder chambers, but he recalled seeing three rounds in the cylinder at the time. (After the shooting, Halls said in the affidavit, Gutierrez-Reed retrieved the weapon and opened it, and Halls said that he saw four rounds which were plainly blanks, and one which could have been the remaining shell of a discharged live round.)^[37] In the warrant, it is further stated that Halls announced the term "cold gun", meaning that it did not contain live rounds.^[35] Halls's lawyer, Lisa Torraco, later sought to assert that he did not take the gun off the cart and hand it to Baldwin as reported, but when pressed by a reporter to be clear, she refused to repeat that assertion.^[38]

B-camera operator Reid Russell was situated on a camera dolly, looking at a monitor with Hutchins and Souza both nearby. The scene involved Baldwin's character removing a gun from its holster and pointing it toward the camera.^[26][30] The trio behind the monitor were two feet (0.6 m) from the muzzle of the firearm and none of them were wearing protective gear such as noise-canceling headphones or safety goggles.^[26]

The trio behind the monitor began repositioning the camera to remove a shadow, and Baldwin began explaining to the crew how he planned to draw the firearm.^[30] He said, "So, I guess I'm gonna take this out, pull it, and go, 'Bang!'"^[26] When he removed it from the holster, the revolver discharged a single time. Baldwin denied pulling the trigger of the gun, while ABC News described a later FBI report stating that the gun could only fire if the trigger was pulled.^[39][40] Halls was quoted by his attorney Lisa Torraco as saying that Baldwin did not pull the trigger, and that Baldwin's finger was never within the trigger guard during the incident.^[41] When the gun fired, the projectile traveled towards the three behind the monitor. It struck Hutchins in the chest, traveled through her body, and then hit Souza in the shoulder.^[27][35][42] Script supervisor Mamie Mitchell called 9-1-1 at 1:46 p.m. MT and emergency crews appeared three minutes later.^[26] Footage of the incident was not recorded.^[32]

Hutchins was flown by helicopter to the University of New Mexico Hospital in Albuquerque, where she was pronounced dead.^[43] Souza was treated by EMS and transported by ambulance to Christus St. Vincent Regional Medical Center in Santa Fe, where he was admitted and released by the following morning.^[44]

As a result of the incident, production on Rust was suspended indefinitely,^[43] though co-producer Anjul Nigam was confident the film would resume production once the investigation ends. However, Nigam later clarified that he meant to express optimism and hope, rather than confidence, as he stated that many involved in the production hope to honor Hutchins by completing her final work.^[45][46]