The story was originally going to be the concept for an episode of X-Files : Aux frontières du réel (1993), which was inspired by L'unique survivante (1984). In this movie, a woman who was the sole survivor of a plane crash starts to be haunted by dead people that Death uses temporarily as vessels trying to kill her to correct its plan, and killing everyone who suspect it.
(at around 4 mins) The shot of Alex's bedside clock, which fades in from 1:00 a.m. to 180, took five days to get correct.
The exterior of Ms. Lewton's house was built in five days. The residents of Vancouver didn't want the filmmakers to blow it up as they thought it was a nice house.
(at around 4 mins) In the opening scene, Devon Sawa (Alex) was supposed to pretend to be asleep. He actually fell asleep for four hours.
Much of the news footage shown is actual footage from the July 1996 explosion and crash of TWA Flight 800 off East Moriches, Long Island, New York.