I dunno, septemeber 11th is a pretty touchy subject for a lot of people...Personally I would avoid it.
But as far as perspectives go there's a few ways. Some subtle, some not so much.
- Have each character use a different coloured text
- Have some sort of header stating who the character is at the begining of each page (or when you switch characters)
- Have the narration change to reflect the character (some characters would be more optimistic, others pessimistic)
- Refer to something that only that specific character could see or have access to. Have characters be in pairs, and simply refer to the other character at times (Like if Tiffany is always with Brian, then Brian will always be mentioned somewhere on the page so the player knows they are Tiffany). You don't need to use a person if you don't want, it could be their setting or maybe a personal item that they have that they would refer to often.