After breakfast, we went to the school auditorium where the wardrobe girls selected four outfits for each extra to wear, all of which were fairly neutral and plain. I commented to the "wardrobe girl" that she had a fun job (playing dress-up, basically), and she agreed.
We waited in the auditorium in our first outfits until one of the assistant directors received the direction via walkie-talkie to move the extras to the cistern, the first site of filming for the day.
There the extras (acting as students and professors) were grouped together as if it were a normal school day. The first scene we filmed featured the main character, a college student played by Amanda Seyfried, walking down the front steps of the building on 9/11 as students were just finding out about the day's events. I was lucky in that I was actually was told to do something dramatic: a girl (she was in my English class last year) had to receive a phone call saying that her parent was a victim in the attack, and I had to embrace her in her hysterical mode. I really enjoyed this dramaticism, but it was starting to get a bit lackluster by the tenth time it was filmed!
If you look at the picture of the cistern, it is open and empty. When we filmed, however, there were at least 25 people working on production doing things I did not fully understand, like setting the lights, carrying reflector screens, measuring the light, directing the extras, controlling the camera, securing the site, etc.; the countless number of details that had to be attended to made the filming process pretty slow and repetitive. However, the experience's novelty (among other details of the day) counterbalanced its negative aspects...
(Part 3 is in pre-production)