Rollercoaster (1999)
Rollercoaster is a 1999 teen drama film directed by Scott Smith. It is about five teens who escape a group home and travel to a defunct amusement park, hoping to find a notorious kid-friendly security guard who will run the rides for them. Although pursuing a fun-filled day, two the teens, a couple expecting a baby, have formed a suicide pact and plan to use the amusement park to carry it out.
More at Wikipedia.