A man can be seen showering at his job at the fire department. His buttocks can be seen briefly for a few seconds. No frontal nudity.

a man in the beginning kicks a puppy

(There is no gore)

A helicopter loses control and crashes inside one of the two buildings, both pilots are killed.

The crash of the helicopter causes fuel to leak, sparks, and as a result a major explosion which leads to a fire that eventually spreads throughout the floors.

Hundreds of individuals inside the building panic and run through the hallways.

Though no one is listening, in the panic, several people attempt to get into an elevator in order to escape (the stairs are on fire). However when a group of people do so, the elevator makes its way down but malfunctions and a fire begins heating it up. The people inside are fried (shoes getting melted, steam, blood, etc) and finally it explodes shortly after.

The explosion makes its way to the elevator doors and several people are caught on fire.

People at the lobby scream (a woman can be seen bleeding from her head) and run outside.

A man who is on fire jumps to his death. [CGI]

Several people are shown falling to their deaths or getting killed by explosions.

Falling debris inside the building kill people.

An old lady too frightened, falls to her death.

An elevator shaft breaks loose and free falls about 7 floors to the ground with people inside. Everyone survives except a man is impaled by a piece of steel, and dies.

In some of the official English subtitle versions, words like Damn, Hell, Ass, Bitch, Bastard, Shit and one use of Fuck is used in the English translation. Although people in the film speak in Korean.

The entire film consists of similar events from the September 11 attacks.

People can be seen on fire, falling to their deaths, suffocating due to smoke, bleeding severely, getting killed by falling debris, burning, screaming, crying, etc.