Two teenagers were arrested Thursday after authorities said they plotted to commit a mass shooting at a Florida middle school.

The 13- and 14-year-old boys were charged with conspiracy to commit a mass shooting after a student told a teacher that one of them had a gun in his backpack Wednesday at Harns Marsh Middle School in Lehigh Acres, about 15 miles east of Fort Myers, Lee County Sheriff Carmine Marceno said during a press conference.

“This could have been the next Parkland massacre, but we stopped them in the planning stages,” Marceno said, referring to the 2018 shooting at Marjory Stoneman Douglas High School that left 17 people dead.

Marceno continued: “We were one second away from a Columbine here. I’m certain that my team of dedicated deputies and detectives acted promptly, investigated thoroughly and prevented a very violent and dangerous act from being carried out.”

Investigators searched an eighth grader’s bag after they were tipped off, but did not find a gun, the sheriff’s office said. Instead deputies found a map of where the school’s security cameras were located.

An investigation determined that the teens were allegedly studying the April 20, 1999, Columbine massacre that was planned by two troubled students who murdered a dozen classmates and a teacher before they killed themselves, Marceno said. Authorities also accused the teens of trying to learn how to construct pipe bombs and how to buy firearms off the black market.

Deputies executed search warrants at both students’ homes and found a gun and several knives, according to the sheriff’s office. In total, Marceno said authorities searched the boys’ home nearly 80 times.

The two boys were evaluated at a mental health facility, according to Marceno.

Harns Marsh Middle School and Lee County Schools District did not immediately respond to an NBC News request for comment Friday.

Principal Alex Dworzanski told NBC affiliate WBBH of Fort Myers that the school was safe.

“I commend the students who came forward to report the threat and the quick action of the staff,” Dworzanski said. “The safety of our students and staff is at the core of what we do.”