The Virgin Suicides
(1999)

The Lisbon girls invite the boys over one night. Lux (Kirsten Dunst) meets them at the door. The boys tell her that they've got a car and can take the girls wherever they want to go. Lux tells them to come inside while she goes to the car. While the boys explore the home's interior, they discover the girls' dead bodies one by one. They run from the house (for help, I guess.)

The film explains all the ways the girls died, from hanging to sleeping pills. While the boys had been exploring inside, Lux closed the garage and turned on the ignition, allowing the gases to fill the garage and she suffocated.

Mr. and Mrs. Lisbon (James Woods and Kathleen Turner) sell most of the things belonging to the girls, including Lux's homecoming queen tiara. They then leave the city. While the city quickly tries to forget the girls' deaths, the boys are never able to.

Thanks Yitz!