Story highlights One of Nicole Cevario's parents warned police that she was allegedly planning a Columbine-style attack on her high school

The 18-year-old's diary said she planned to carry out the attack on April 5, police said

(CNN) Nichole Cevario's journal was not your typical high school diary.

Rather than writing about schoolwork or personal relationships, the 18-year-old allegedly detailed her plans for a Columbine-style mass shooting at her Maryland high school, according to law enforcement.

And officials are convinced those plans might have come to fruition if one of her parents hadn't told school officers about them, the Frederick County Sheriff's Office said on Monday.

Police searched her home and found a shotgun with ammunition as well as materials for making pipe bombs, including pipes, shrapnel, fireworks, magnesium tape, and fuse material, police said.

Police found a shotgun at the student's home.

"There's no doubt in our minds that we averted disaster there," Sheriff Charles Jenkins told reporters. "I've never seen anything like this, to be honest with you."

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