"It was the work of a very courageous student who came forward," Bond said. "It could have been a disaster."
Bailey Gerhardt, a 16-year-old sophomore at Roy High School, said she received a text message from the 16-year-old boy involved asking, "If I told you to stay home on a certain day, would you?" She said she told police about the message on Thursday, as authorities continued to question students.
Gerhardt said the boy had told her he had looked into the shootings of students at Colorado's Columbine High School. At one point, Gerhardt said he told her he had flown to Colorado "to check it out." Gerhardt characterized the boy as an angry person recently dumped by a girlfriend.
Recently, Gerhardt said the boy took her and a friend for a ride in his truck and refused to take them home for hours. Mekaila Taylor, also 16, confirmed Gerhardt's account and said the boy had talked about Columbine to a number of his close friends.
The plot "was months in planning," Whinham said, and included plans for a device designed to "cause as much harm as possible to students and faculty" at the high school.
On Wednesday, the Weber County Bomb Disposal Unit, Alcohol Tobacco and Firearms and bomb-sniffing dogs from several law enforcement agencies were enlisted to search the school buildings and grounds.
Also Wednesday, police executed four search warrants on two houses and two automobiles and seized four computers. Forensic specialists will evaluate the computers for evidence in the case, Whinham said.
"We believe key information will come from the computer databases," he said. "When we can evaluate what's in the computers, we can begin to fill in the blanks." The chief said he would like to know the motivation behind the alleged plot.
"These appear to be normal young men. Part of the investigation is to know what was the motivation, the trigger."
No explosive materials were found during any of the searches, Bond said.
"But we do know these individuals have made explosives in the past," she said.
Investigators did find flight simulation training programs and the suspects appeared to have logged "significant" hours on them, Bond said.
Follow-up interviews with students led investigators to believe the suspects may have been planning an escape by stealing an airplane at the Ogden airport, Bond said.
During the course of the searches, investigators also turned up maps of the school and its security system.
"We're working to assess the threat and how viable the plan was," Bond said.
Classes were being held on normal schedules at the high school on Thursday.
Morgan was booked into Weber County jail on suspicion of conspiracy with bail set at $10,000. The 16-year-old was in custody at the Weber Valley Detention Center. Other charges may follow as the investigation continues. The Salt Lake Tribune generally does not name juveniles suspected of criminal activity.
"We are in the very early stages of this investigation," Bond said.
Most of the students leaving Roy High on Thursday afternoon said they weren't worried about the bomb scare.
"They told us it was safe and not to be worried," said Marina Brown, 16. "It was just really odd to hear about something like that here."
Jordan Townsend, a 15-year-old sophomore, said teachers seemed "a little jumpy" Thursday. "I thought it was made up at first. I met them once," he said of the suspects. "They're just regular kids."
The parents of the two boys did not wish to comment.
Tribune reporter Cimaron Neugebauer contributed to this story