Parents Disarm 15-Year-Old Who Fired Gun at Utah Junior High School: Police

— -- A Utah junior high school was placed on lockdown today after a 15-year-old fired at least one round in a hallway -- but the teen was disarmed by his parents, who came to the school after being concerned that guns had gone missing from their house, police said.

Police dispatchers received a 911 call form a Mueller Park Junior High School teacher around 8:15 a.m. who stated that there was an individual in the school firing a weapon, according to Bountiful City Police Chief Tom Ross.

The teen's parents had gone to the school to look for their son and arrived before the shot was fired, Ross said. After they heard the gun go off, they were able to find and disarm him, Ross said. An officer arrived on scene within two minutes of the initial 911 call, and the teen was then taken into custody.

Police said the teen entered a classroom with 26 students and fired a shot to the ceiling. He did not speak to anyone in that instance, they said.

A shotgun and a handgun were recovered from the scene, as well as additional ammunition, police said. It is unclear which weapon was discharged.

The teen's parents went to the school because they were "worried" about their son and were "concerned that there were weapons missing from the home," Ross said. Police said that they also believed their son had been acting strangely. Someone had also tried to talk him out of carrying out the act, police said.

A motive is not known at this time. No others were involved in the ordeal, and the it is unclear if there were any targets, police said. The teen is being held in a juvenile detention center. No charges have been filed as of yet.

More than 100 law enforcement and emergency personnel responded, Ross said. The police department has done several drills over the years ever since the 1999 mass shooting at Columbine High School in Colorado.

The Davis School District announced that the lockdown had been lifted around 11 a.m., and school remained in session. Parents were not required to take their students home, but those who wished to were instructed to get their children from a nearby church. ABC News could not immediately reach the school district for comment.

Stephanie Neslen, whose son attends the school, said the drive to pick him up was the longest in her life.

"He texted me and said, 'Mom, it's not a drill. I heard a gun,'" Neslen told ABC Salt Lake City affiliate KTVX.