Updated

An Ohio student, who fatally shot himself in his school’s restroom last week intended to carry out a school shooting “bigger than anything this country’s ever seen,” authorities said.

Seventh-grader Keith Simons, 13, concealed a .22-caliber gun under his shirt as he rode a bus to Jackson Memorial Middle School on Feb. 20, where he reportedly went to the restroom immediately and shot himself, FOX 8 reported.

In a news release Thursday, Jackson Township Police Chief Mark Brink said a memo discovered on Simons’ phone revealed the teen’s “fascination with school shooters, specifically the Columbine shooters,” referring to the 1999 massacre in Colorado.

Simons intended to conduct his own school massacre “with an eight-step plan,” FOX 8 reported.

A portion of an entry dated Feb. 19 reads:

“(T)his will be bigger than anything this country’s ever seen, … I’ve been planning this for a few weeks and thought about it a few months, I will never be forgotten I’ll be a stain in American history and the Simons history, it’s going to be so mutch [sic]. They won’t expect a thing.”

"I’ve been planning this for a few weeks and thought about it a few months, I will never be forgotten I’ll be a stain in American history and the Simons history, it’s going to be so mutch [sic]. They won’t expect a thing."

— Entry on Keith Simons' phone, according to police

Before fatally shooting himself, Simons walked out of the restroom with the weapon and then returned, where another boy saw the gun and reported it to school officials, FOX 8 reported.

"Why he went back into the bathroom after he came out holding the gun and then committed suicide? We don't have an answer," Brink said, according to the station.

Police have yet to discover any further evidence to what might have led Simons to change his mind from conducting a school shooting to taking his own life. It doesn’t appear anyone else was aware of Simons’ plans, the station reported.

The investigation is ongoing.