The character Alex is loosely based on a real individual from a documentary Carlson directed back in 1999. The other characters are entirely fictional.
The film was written during the period in which the film takes place. 911 was always in the film, but there was never any intentions to make it more than the setting of the piece.
The film was shot in New York. There were only two days shot outside of the city, on a sound stage in upstate. Carlson made an effort to really make the film enclosed, tight and claustrophobic .
Carlson wanted to make a poetic film, while using music as a subconscious backdrop. Story wise, music plays a big part in the mindset of the main character.