On the night of July 23, 1993, street kids expecting a charity handout rushed a group of cars outside of the Candelaria Cathedral in Rio de Janeiro. Off-duty police officers got out of the cars, gunfire ensued and eight dead children remained.

One of the survivors, Sandro do Nascimento, after years of petty crime and visits to jail, hijacks a bus in a nationally televised incident that is the subject of the harrowing Brazilian documentary "Bus 174."

On June 12, 2000, Nascimento tries to break out of his invisibility acquired in growing up as a street kid.

Director Jose Padilha includes a focus on the previously mentioned Candelaria massacre to provide essential background that helped shape the desperate man Nascimento became.

Padilha achieves an astonishing depth of character development for Nascimento, given the limited footage and dialogue of Nascimento himself. The editing constantly interweaves coverage of the present hostage situation with glimpses into Nascimento's past.

Padilha establishes the documentary's tone in the opening overhead shot of downtown Rio, with multiple narrators describing an urban youth's life on the streets.

The gorgeous aerial views of the city contrast with the stark live footage focused on a bus, mostly consisting of a man holding a gun to a woman's head.

The intensity and complexity of the situation gradually increases. Nascimento makes the woman write on the windows, "He is going to kill me at 6 o'clock," and often reminds the police of this ultimatum.

Members of the S.W.A.T. team recount the great number of opportunities — such as every time Nascimento sticks his head out of the window to shout something at the police — they had to end the situation by taking Nascimento's life with a bullet from a sniper rifle. But does a national audience want to see a man's head blown off?

As the bus scenes build to excruciating levels of tension, Padilha cuts to an astounding series of interviews with prisoners in Rio's overcrowded prisons. The film is overexposed to the point that the prisoners appear as animals, as they decry the injustices and inhumanity of the system and the prison itself. One prisoner says the authorities have not even notified his family of his incarceration, which is probably the least disturbing complaint from the prisoners.

There is no camera inside the bus, so the narration of the woman who was inside provides the only insight concerning what Nascimento told his hostages. An unforgettable moment late in the movie involves the woman revealing an inconsistency between Nascimento's shouts to the police and his orders to the hostages, which significantly alters the viewer's perception of his character.

By the time Nascimento's aunt reveals what happened to his mother when he was a child, Padilha has peaked in his investigative reporting abilities by finding out the grim causes of this media extravaganza.

The climax is simple and inevitable as tragic chaos envelops the bus.

The viewer for the first time realizes the widespread significance of this event, as hundreds of onlookers — in a breathtaking surge — rush the scene, forming a stampeding mob.

Padilha handles the subject matter with grace and gritty realism, and he has vigorously sought the truth from all angles of a social tragedy that transcends a bus hijacking.