Alec Baldwin fired a prop gun Thursday, Oct. 21 that killed the director of photography, Halyna Hutchins, and injured director Joel Souza of the new movie “Rust.”

Baldwin was practicing drawing his gun during a rehearsal when the gun went off, according to CNN. The gun he was using to practice with was an actual loaded weapon given to the actor by the assistant director, David Halls. USA Today published an article saying that Halls didn’t know that the weapon was loaded with live rounds and indicated that it was safe.

“…[W]hat happened on the set was that a real gun was on the set and there were real bullets, which is totally against the safety code,” Dr. Mary Beadle, a professor of Communications at John Carroll University, stated.

Yale’s undergraduate production program defined prop guns as “non-firing weapons, rubber guns and toy guns.” The program also stated that a prop weapon can be “capable of inflicting bodily harm,” which is why they need to be handled with a high level of caution.

Halls doesn’t have the best reputation when it comes to props. According to three crew members who had worked with him before on another movie called “Freedom’s Path.” CNN reported that during the filming of this movie, a gun unexpectedly discharged. The crew members reported unsafe conditions before Halls was fired from the project.

While filming “Rust,” and just hours before the shooting, crew members allegedly walked off set to protest working conditions. USA Today said that crew members were raising concerns about several problems, including safety.

“Any prop can be dangerous depending [on] how it is used and how safety guidelines are followed. It is not about the prop but about the people who are using the prop. Have they been properly trained, and do they have sufficient experience to be using the prop safely?” Beadle explained.

The investigation is still ongoing, but no charges have been filed against the actor or the project itself. Baldwin said that he is fully cooperating with the police. He released a tweet addressing the death of Hutchins, “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.”

As the investigation continues, more information about the incident will be released in the coming days.