SALT LAKE CITY (AP) -- The two teens had a detailed plot, blueprints of the school and security systems, but no explosives, authorities say. They had hours of flight simulator training on a home computer and a plan to flee the country, but no plane.
Still, authorities say, both Utah high school students were deadly serious about a plot to bomb the roughly 1,500-student Roy High School, about 30 miles north of Salt Lake City, during an assembly.
A 16-year-old, along with Dallin Morgan, 18, were arrested at the school Wednesday after authorities were alerted to the plot by a fellow student who received ominous text messages from one of the suspects.
"If I tell you one day not to go to school, make damn sure you and ... are not there," the message read, according to court records.
Authorities on Friday were trying to determine just how close the two suspects were to pulling off the attack they say was inspired by the 1999 Columbine High School shootings in Littleton, Colo. Students Eric Harris, 18, and Dylan Klebold, 17, opened fire on classmates there, killing 12 kids and a teacher and wounding 26 others before killing themselves.
Morgan was released on bond Friday morning, pending arraignment. The 16-year-old, whom The Associated Press isn't naming because he's a minor, had been held at a juvenile facility but authorities declined to immediately say whether he remained in custody Friday.
Both suspects were arrested on suspicion of conspiracy to commit mass destruction. Prosecutors are weighing additional charges.
The suspects told authorities they were inspired by the Columbine shootings, but were offended when compared to them because "those killers only completed one percent of their plan," according to a probable cause statement.
Roy High School sophomore Bailey Gerhardt told The Salt Lake Tribune she received text messages from one of the suspects and alerted school administrators.
"I get the feeling you know what I'm planning," read one of the messages, according to court records. "Explosives, airport, airplane.
"We ain't gonna crash it, we're just gonna kill and fly our way to a country that won't send us back to the U.S.," read one message to the girl.
While authorities are still working to determine a motive, one text message noted the suspects sought "revenge on the world."
Police credit the girl with helping foil the plan, though authorities said the school didn't have any assemblies set, and the suspects revealed no specific dates to pull off the attack.
"It could have been a disaster," Roy police spokeswoman Anna Bond said.
The juvenile suspect also told investigators he was so "fascinated" by the Columbine massacre that he visited the school and interviewed the principal about the shootings.
Columbine Principal Frank DeAngelis confirmed Friday he met with the 16-year-old student on Dec. 12 after the teenager told him he was doing a story for his school newspaper on the shootings.
DeAngelis told the AP he frequently gets requests from students doing research on the shootings, and the request from this one wasn't unusual.
"He asked the same questions I get from many callers and visitors asking about the shooting," DeAngelis said. He said the student wanted details about the shooting, the aftermath and the steps taken since then to protect the school.
Police said the student told them Roy school officials would not allow him to write the story.
DeAngelis said he was shocked when he got a call from Utah police on Wednesday asking if he had met with the youth. He said the interview raised no red flags but that he would do things differently with future requests.
"This was definitely a wake-up call. This is the first time this has happened," DeAngelis said.
The Roy High School plot "was months in planning," said Roy police Chief Gregory Whinham, and included plans for a device designed to "cause as much harm as possible to students and faculty" at the school.
The FBI is examining the suspects' computers. Local and federal authorities searched the school, two vehicles belonging to the suspects and their homes but found no explosives.
Morgan told police the 16-year-old suspect had previously made a pipe bomb using gun powder and rocket fuel.
"Dallin told me that (the juvenile) bragged about using a bomb to blow up a mail box and having three handguns in his house," according to a police affidavit. The 16-year-old boy "claimed that he did not have the guns but Dallin was the source of the guns because he is 18 and can purchase a gun."
The two students prepared by logging hundreds of hours on flight simulator software on their home computers, and they planned to steal a plane from nearby Ogden Hinckley Airport after the bombing, Bond said.
Both students had "absolute knowledge of the security systems and the layout of the school," Bond said. "They knew where the security cameras were. Their original plan was to set off explosives during an assembly. We don't know what date they were planning to do this, but they had been planning it for months."
The parents of both students "woke up in the middle of a nightmare," Bond said. "They've been very cooperative."