The violent and disturbing images in this movie are incredible for a PG-13. While it would not be R content, it still is far more bloody, shocking and disturbing than an 11 or 12 year old could handle, regardless of if they are squeamish or not.
The sections in red are highlighted for parents to consider before bringing an underage person to see this movie. Like I said, the movie itself does not qualify for an R rating despite the content and the nature of the violence, but it is incomparable to most PG-13s due to the fact that the violence is indirectly slasher-style and somewhat bloody/shocking.
People die in violent and sudden ways, but only some scenes are bloody, and there are no gorey details.
An elevator containing a dead older woman, a dead man, another bloody and dead man (we see a piece of glass sticking out of his throat), a young woman and a man goes dark: we hear a thud and some panting, a woman screams as a slicing sound is heard, the man is shown holding the young woman in his arms with blood covering her and the man's hands, and it appears that her throat has been cut and she is seen bleeding to death.
Glass is heard breaking and shards fall over a man standing in an elevator with an older woman, a young woman and three men; the elevator goes dark and we hear what sounds like a woman panting, a loud thud and a slicing sound, and when the lights come back on we see a man lying on the ground with a piece of glass sticking out of his neck (blood pools on his neck and body).
An elevator where two men and a young woman are standing (the dead body of a woman and the bloody dead body of a man are seen slumped in a corner of the elevator) goes dark: they attempt to light the area with their cell phones, the phones are knocked out of their hands and the sound of bones crunching is heard; when the lights come back, one of the men is seen with his head turned 180 degrees.
We hear a sharp intake of breath as the screen goes black and a woman screams as a mechanical grumble is heard; the lights return, a woman is seen hanging in an elevator with an electric cord wrapped around her neck, presumably dead, two men lift the woman's body, unwrap the cord from her neck and set her body next to the bloody body of a dead man.
A man and a woman are in an elevator with the dead bodies of two men and a woman, and they grab pieces of broken glass (we see blood on their hands) to use to defend themselves, while accusing each other of killing the people in the elevator. This scene is particularly intense.
An elevator containing several dead bodies, a wounded person and a man goes into free fall: we hear growling, the elevator comes to a sudden stop, the doors are pried open and we see bloody bodies and a man covered in blood (we later see body bags being wheeled away from the scene.)
A man rappels down an elevator shaft, loses his balance and flips over, unhooking his support carabiner; his body falls and a thud is heard from inside the elevator as a woman, a young woman and two men (we also seen the bloody dead body of a young man on the floor) lurch forward when it is implied the man's body hit the top of the elevator (blood is seen pooling on the ceiling of the elevator and the man's mangled body is later seen multiple times).
We see an apparently inebriated young man driving wildly. He crashes into another car, struggles to get out of his car (he has small cuts on his face and his nose is bleeding), and approaches the other car where we see a woman, gasping for air as blood gurgles from her mouth, and the lifeless body of a young boy (we only see the boy's back since he is lying face-down on the ground); the young man then drives away from the scene.
A body is seen dropping from the sky and slamming into the top of a delivery truck; we see the slightly crushed truck and the bruised hand of the dead person as two police officers discuss how it had been a suicide.
Sparks fly from a frayed wire sitting in a puddle, a man tries to pull the wire out of the puddle, and we see him, face mangled and shirt covered in soot, wander through a crowd; we hear women and men screaming as they move away from the man and then fall to the ground, presumably dead from electrocution.
A man tries to climb out of the emergency hatch on an elevator when another man inside drags him back in and he falls on top of the bloody dead body of a man with a piece of bloody glass sticking out of his neck.
A woman, a young woman and three men are seen in an elevator, one of the men starts hyperventilating (he says he is claustrophobic after his brother had locked him in a car trunk as a child), the elevator goes black and we hear a woman scream; when the lights come back on, the young woman is lying on the ground, she struggles to stand up, we see a bloody cut on her back, and she says it feels like something bit her.
On multiple occasions both a young woman and two men experience momentary mental images of a group of dead men and women lying on the floor of an elevator; they are covered in blood.
A group of men watch security footage of a man's dead and bloodied body (a man says that the man had been stabbed in the jugular and it could not have been an accident).
Two men standing on a sidewalk narrowly avoid being hit by a large piece of glass that drops from a tall building.
An elevator goes into free-fall, as a man watches from the bottom of the elevator shaft, and lands with a thud on the ground; the man standing at the bottom of the elevator shaft is protected by a cage that surrounds him, and he is unharmed.
Two men in an elevator wrestle, one of the men slams the other man's face into the wall as a young woman watches and cries, until a man watching on a security camera shouts at them to stop and they separate.
A woman threatens a man with a pepper spray.
A man tells another man and a young woman that he had previously beaten up a person that he established to be causing a "rift" in his community, and implies that he will do the same to a young woman if she does not stop trying to get two men to fight.
A man tells a man and a young woman that he had witnessed a lot of deaths when he spent time in Afghanistan and the other man wonders whether he was trained to kill people.
Two men discuss the criminal past of a young woman.
A man reads a person's criminal record aloud, saying that he had been charged with assault multiple times, including beating a man into a coma.
A man confesses to having killed a woman and a young boy in a hit-and-run accident.
A man tells another man that his wife and son had been killed in a hit-and-run accident.
An older woman asks if an elevator could fall multiple stories and a man reassures her that it will probably not happen.
A Bible verse is heard being read by a male voiceover, and it states that the devil is going to devour people.
In a voiceover a person says that his mother had told him stories as a child about how the devil is going to gather people together and torture them before killing them; also, a suicide leads to the devil being present and leaving only after a person watches their most loved person die in front of them.
An elevator containing a woman, a young woman and three men jumps and then comes to a quick halt; the occupants are jolted but unharmed.