The sequence of events on set that led to Alec Baldwin accidentally shooting and killing cinematographer Halyna Hutchins remains unclear, but industry experts and past, similar tragedies indicate only a handful of options for what may have happened.
The most obvious option now is that the actor accidentally fired a live round, thinking it was a blank, after being handed the weapon by either a prop master or armorer.
After firing the shot, Baldwin was heard saying: 'In all my years, I’ve never been handed a hot gun.'
IATSE 44, the biggest union to represent film prop masters, also told its members that she was struck by a live round and not a blank.
How exactly that live round found its way into the gun remains unconfirmed but there are some options.
SQUIB LOAD: Real bullet was lodged in the barrel of the gun when Baldwin fired a blank
One possibility is that an object was stuck in the barrel of the prop gun that Baldwin was using. Known as a squib load, it happens when a cartridge isn't fired from the barrel because the gas isn't strong enough to push it out.
In itself, it is not dangerous and can be fixed if the gun is safely cleared but if someone keeps firing rounds from that same gun - live or not - it can be highly dangerous.
If a second round is fired behind the stuck round, it can cause the weapon to explode, or injure people in the near vicinity.
Alec Baldwin is pictured sobbing after shooting and killing cinematographer Halyna Hutchins on the set of his upcoming movie Rust in Santa Fe, New Mexico, on Thursday
The 68 year-old actor was also snapped doubled-over in a parking lot, with his hands on his knees and his face seemingly crumpled with distress
The difference between live rounds and blanks is the tip of the cartridge where the lethal bullet is contained is not there on a blank. Sometimes they are replaced with cotton or paper. Dummy bullets, unlike blanks, look like ordinary bullets but aren't meant to contain the metal bullet tip either
If a real bullet was stuck in the gun when it was loaded with blanks and Baldwin pulled the trigger, it may have forced the
