Mark Wahlberg admitted that he regrets working on this movie, but said, "You can't blame me for wanting to try to play a science teacher. At least I wasn't playing a cop or a crook."
The movie was shot completely in sequence.
On June 8, 2008, days before the first few reviews for the film came online, M. Night Shyamalan told the New York Daily News: "We're making an excellent B movie, that's our goal."
M. Night Shyamalan: The voice of "Joey," who calls Alma a few times throughout the movie. The audience never sees him nor learns of his fate.