A teenager, recently reported missing, was found unconscious near Upper Otay Lakes Dam and now San Diego County sheriff's deputies have launched an investigation to determine what killed her.
The 16-year-old girl was found just before 6 p.m. Monday along the base of the dam after someone called deputies.
She was found unconscious, but breathing, officials said.
Emergency personnel airlifted the teenager to Scripps Mercy Hospital. She was pronounced dead at the hospital hours later.
The family of the teen has identified her as Reyna Genel (pictured below), a Mater Dei Catholic High School student.
Her older sister said Reyna had gone running alone, when hours later she was found at the bottom of the reservoir. 
Around 6 p.m. on Monday, her father got worried and called police. Around that same time, the sheriff's department was responding to a call at Otay Dam.
Officials say the teen may have fallen off a concrete wall and landed in the lake bed.
Sheriff's homicide is now investigating this incident due to its circumstances and the fact that the victim is a minor.
Anyone with information about this incident can call investigators at (858) 974-2321/after hours at (858) 565-5200.
School officials at Mater Dei said they're planning a vigil in the teen's honor some time this week.
Photo Credit: NBC 7 San Diego