This combination of undated photos released by the Jefferson County, Colo., Sheriff's Office on Tuesday, April 16, 2019 shows Sol Pais. On Tuesday authorities said they are looking pais, suspected of making threats on Columbine High School, just days before the 20th anniversary of a mass shooting that killed 13 people. (Jefferson County Sheriff's Office via AP)
This combination of undated photos released by the Jefferson County, Colo., Sheriff's Office on Tuesday, April 16, 2019 shows Sol Pais. On Tuesday authorities said they are looking pais, suspected of making threats on Columbine High School, just days before the 20th anniversary of a mass shooting that killed 13 people. (Jefferson County Sheriff's Office via AP)

A Florida teenager who authorities say was obsessed with the Columbine school shooting and may have been planning an attack of her own in Colorado just days ahead of the 20th anniversary was found dead Wednesday in an apparent suicide after a nearly 24-hour manhunt.

Jefferson County Sheriff Jeff Shrader said 18-year-old Sol Pais was discovered by the FBI with what appeared to be a self-inflicted gunshot wound.

The manhunt had led to the closing of Denver-area schools as a precaution, with classes and extracurricular activities canceled for a half-million students.

During the urgent search, the FBI said Pais was โ€œinfatuatedโ€ with the 1999 mass shooting at Columbine High School and made threats against the Denver area ahead of Saturdayโ€™s anniversary of the attack that killed 13 people.

The Miami Beach high school student flew to Colorado on Monday night and bought a pump-action shotgun and ammunition from a gun shop in Littleton, not far from Columbine, authorities said. The FBI described her as โ€œextremely dangerous.โ€

โ€œWeโ€™re used to threats, frankly, at Columbine,โ€ John McDonald, executive director of security for the Jefferson County school system, said when the manhunt was over. โ€œThis one felt different. It was different. It certainly had our attention.โ€

Her body was found off a trail not far from the base of Mount Evans, a popular recreation area about 60 miles southwest of Denver, authorities said.

McDonald described her trip as a โ€œpilgrimageโ€ to Columbine and cited her purchase of the shotgun as one reason officials took her as a serious threat.

โ€œThose two things combined with her fascination of Columbine โ€“ thatโ€™s pretty clear and convincing evidence that she was a threat to the school,โ€ he said.

Colorado Gov. Jared Polis said after receiving word that the hunt was over that he and all Colorado parents are โ€œhugging their children a little tighter.โ€

Authorities said Pais was last seen not far from Columbine โ€“ in the Jefferson County foothills outside Denver โ€“ in a black T-shirt, camouflage pants and black boots. Police were instructed to detain her for a mental health evaluation.

The sheriff said the sale of the shotgun apparently followed the stateโ€™s legal process.