A smoking backpack was discovered in the cafeteria of Pine View High School in St. George, Utah Monday. Police later determined the backpack contained a bomb which could have done significant damage if it had gone off. An unnamed student was arrested and charged with creating a weapon of mass destruction. The same student had recently taken an interest in ISIS. From the St. George News:

“After examining the device, bomb squad members indicated that if it had detonated; the device had the potential to cause significant injury or death,” the St. George Police said in a statement.

The backpack was left in the cafeteria of the high school during lunch where some students noticed it smoking. They alerted the resident school resource officer and faculty, which led to the school’s 1,100 students being evacuated to the football field for the rest of the school day…

The police executed a search warrant at the home of the suspect, identified as a juvenile male attending Pine View High School, where investigators found “materials consistent with the materials used to build the device.”

In addition to finding bomb-making materials, the Associated Press reports authorities also found evidence the student had been “researching” ISIS and was connected to an incident at another high school last month:

It was also determined that the male had been researching information and expressing interest in ISIS and promoting the organization,” police said.

Police in the city of Hurricane about a half-hour drive from St. George said Tuesday the teen who was arrested is also suspected of raising an Islamic State group flag in February at Hurricane High School. That happened on Feb. 15, a day after a mass shooting at a school in Florida. Authorities initially thought the graffiti and flag at the school were pranks…

Hurricane Police officer Ken Thompson confirmed “charges are pending on our incident here with the flag.”

“When the search warrant was executed, there was evidence taken from the house that tied him to our case,” he told The Associated Press Tuesday afternoon.

When the ISIS flag was raised at the neighboring high school, someone also spray-painted “ISIS is comi[ng]” on the outside of the building. Authorities contacted the FBI who determined the person responsible was not likely connected to ISIS. That appears to be true but it seems, in retrospect, that authorities underestimated the seriousness of the threat.

One thing that’s still not clear is how serious the bomb itself was. One student who looked at the backpack said he thought it looked like a box of matches. Obviously, there was more to it than that but police are being very specific. Where did this student get the materials and the information to build the bomb? So far, no one is saying.