The entire film was shot in the rain so that create a dark, grisly atmosphere.
Brad Pitt put his arm straight through a windshield.
There were severed tendons, exposed bone, and buckets of blood.
CineFix
However, the movie was shot out of sequence which means his cast is hidden in some earlier scenes.
A scene was shot where Robert Kennedy was assassinated.
In 1968, Kennedy was assassinated in the Ambassador Hotel (depicted above).
In 1995, one of the bungalows of the old Ambassador Hotel was used as a film set.
It acted as the safe house where Somerset and Mills interview the widow of the murdered lawyer.
The man in the gluttony scene was covered in real, live cockroaches.
Minolta DSC
True to the name of the film,sevencrates of cockroaches were released for the gluttony scene.
Vaseline was used for see to it the bugs remained on set.
The man in the greed scene was made immobile by blood.
Minolta DSC
Gene Borkan played the victim in the greed scene.
While stripped down to his underwear, he was hog-tied and covered in two gallons of fake blood.
BONUS:Although this didnt occur behind the scenes, its still worth noting.
It is shown at 1. hour and 52 minutes and 53 seconds.
So… who wants to rewatchSe7en?
