Before their son could do any serious damage, fast-acting Utah parents who noticed two family guns were missing Thursday morning tracked him down in a junior high classroom and quickly disarmed him, authorities said.

He had been behaving oddly that morning when he left for Mueller Park Junior High School, troubling his parents, according to the Bountiful City Police Department. Their concern only grew when they realized, after he departed, that the space in their gun safe where a shotgun and pistol usually sat was empty.

The parents rushed to Mueller Park to find their son, authorities said, but as they walked down a hallway, searching, they heard the blast of a gunshot.

Inside a classroom nearby, filled with a teacher and 26 students, the teen had fired one round into the ceiling, leaving behind a plate-size hole.

His parents were soon there, police said, and immediately “disarmed him, then physically detained him.”

Immediately after, at 8:13 a.m., a 911 caller alerted police, and a patrol officer in the area arrived at the school 41 seconds later, authorities said. The teen was arrested and later booked into the Farmington Bay Juvenile Detention Center on multiple charges, including theft of a firearm and taking a weapon into a school, reported the Associated Press.

Authorities recovered a 12-gauge shotgun, 9mm pistol and ammunition for each gun.

At a news conference Thursday, police Chief Tom Ross told reporters that he initially feared a more tragic outcome.

“I was expecting much worse than what happened,” he said. “To have this event unfold at a junior high school and have no injuries — including to the suspect — is pretty amazing.”

The teen’s parents — who detected his peculiar behavior and wasted no time investigating, then acting — exemplify a growing trend of teachers and guardians who have internalized one of law enforcement officials’ new favorite phrases: “When you see something, say something.”

It has been nearly two decades since one of America’s most infamous school shootings, at Columbine High in Colorado, thrust the country’s psyche into a dark, yet increasingly necessary place. In the aftermath of that massacre and the many other school shootings that have followed, schools nationwide have implemented more stringent safety protocols: lockdown drills, active shooter exercises, bulletproof glass and security checkpoints.

But beyond that, each mass shooting, whether at a school, a nightclub or a staff Christmas party, has prompted the country to grapple with the same set of uncomfortable questions.

Could we have known?

Did you see this coming?

Did I?

An alert Florida parent stopped a 13-year-old boy from carrying out a possible plan to harm classmates in March, authorities said, when the parent noticed the boy was trying to hide an AR-15 rifle under clothes while leaving for school.

An alleged mass shooting plot or “something more catastrophic” was prevented in October, Las Vegas authorities said, when a “nosy parent” from neighboring Arizona eavesdropped on a Skype conversation their child was having that mentioned the targeted high school. The plot, authorities said, was uncovered “in part thanks to a parent being nosy, thanks to a parent paying attention, thanks to a parent who did not sit on information and brought that information forward.”

And a possible tragedy was avoided in Tennessee in September when a middle school counselor persuaded a 14-year-old boy, who had come to school with a gun and plans to kill teachers and a police officer, to hand over his weapon. Police there said the counselor expertly defused the situation in a way that “most experienced law enforcement might not do.”

“Had she not been there,” the local sheriff said at the time, “it could have been very different.”

On Thursday, authorities in Utah offered the same praise to the quick-thinking parents, as well as a teacher and a student in the classroom, who tried to talk down the shooter in the minutes before the gun went off and his parents disarmed him.

“A teacher and a student in that room immediately engaged him verbally in trying to talk him out of doing this,” Chief Ross said at the news conference. “I believe those seconds played a big role on the outcome.”

Calvin Smith, who was inside the ninth-grade earth science class where the shot was fired, told the Salt Lake Tribune “it was terrifying” when the armed student walked inside wearing a large black trench coat. The armed teen looked angry, Smith said.

Another student in the classroom pleaded with the teen, Smith told the newspaper, saying, “You don’t want to do this.”

At one point, the teen pointed the shotgun at his own neck, but never aimed it at other students, police said.

Smith told the Tribune that students dived to the ground and that his female classmates cried. The boys did not, Smith said, but he wanted to.

Another student in the classroom, 15-year-old Dan Fowers, told the AP that the armed teen came into the room minutes after class began, fired the shot and was quickly disarmed by a woman, who grabbed the gun and told him to stop. She pulled the boy into the hallway, Fowers said.

“It was really scary,” Fowers told the AP. “The look on his face, it kind of looked like he wanted to do some damage.”

The 911 call made after the teen was apprehended demonstrated just how chilling the moment was for those in the classroom.

“We have a kid with a gun,” the female caller can be heard telling the dispatcher. “His parents have him.”

“He has a gun?” the 911 dispatcher asks, sounding shocked.

“Everyone is safe,” the caller adds reassuringly. She says the parents are concerned about him, that they had him against the wall like they were arresting him.

“Did he actually fire any rounds?” the dispatcher asks.

“He did,” the caller says.

The school, 11 miles north of Salt Lake City, remained on lockdown as more than 100 officers swept the building, room by room, looking for possible dangers, reported the AP. The school educates about 840 students in seventh through ninth grades and is in a predominantly Mormon community.

Hundreds of parents waited in the snow across the street for their children to be dismissed, reported the AP, and by 11 a.m. officials allowed the students to leave.

Bountiful City police said Thursday that the investigation is ongoing, as they try to determine the suspect’s motive and intent.

More from Morning Mix: