A 16-year-old high school girl was found dead and a 15-year-old seriously injured when they fell from a dam in Morioka, Iwate Prefecture, it was revealed Wednesday.
The police are investigating the case as a possible suicide.
Morioka Fire Department officials found the two lying side by side on a slope inside the Shijushida Dam reservoir after receiving a call from an acquaintance at around 1 a.m. Tuesday.
The girls appeared to have jumped from a passageway about 20 meters above the slope, they said.
The dam is located roughly 7 km north of JR Morioka Station.