LITTLETON, CO (CBS NEWS) – Sol Pais, the 18-year-old woman suspected of making threats against Denver-area schools including Columbine High School, has been found dead, officials say. Investigators closed in on the teen Wednesday near the Echo Lake Lodge at the base of Mount Evans in Clear Creek County, CBS Denver reported.

Officials said at a press conference Wednesday Pais was found dead of an apparent self-inflicted gunshot wound.

Authorities had been tipped off to the campground in the Arapaho National Forest by a rideshare driver who dropped her off there, and federal and local law enforcement teams were waiting until daylight on Wednesday before beginning an expanded search of the area, according to FBI Denver special agent in charge Dean Phillips.

Authorities had been conducting a massive manhunt for the Florida teen they described as “armed and extremely dangerous,” saying she was “infatuated” with the Columbine school shooting. The alleged threats led to the closure of school for more than half a million students on Colorado’s Front Range Wednesday. The threats came days before the 20th anniversary of the deadly shooting at Columbine High School, which left 13 students and teachers dead in 1999.

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