The Happening (2008)

A science teacher, his wife, and a young girl struggle to survive a plague that causes those infected to commit suicide. The film opens in New York, where people start to exhibit strange behavior and commit suicide. The protagonist, Elliot Moore, an environmental science teacher, along with his wife Alma and Julian, a math teacher, flee Philadelphia on a train. They learn that the suicides are not caused by a terrorist attack, but by a natural phenomenon. They embark on a journey to find safety, encountering infected individuals along the way. They eventually find refuge in a small rural town, but realize that the toxin is triggered by large groups of people. They split up into smaller groups and continue their journey. Elliot, Alma, and Jess, a young girl they meet, find shelter in an old house with an eccentric old lady. They survive the peak of the attacks and, three months later, return to their normal lives in Philadelphia. However, the film ends with a hint that the phenomenon may be happening in other places.