A female middle school student opened fire on classmates in Rigby, Idaho, on Thursday, officials said.
Two students and one adult were injured, police said. The adult was treated and released from Eastern Idaho Regional Medical Center, while the two students — one girl and one boy — had non-life-threatening injuries, officials said.
Both will remain in the hospital overnight, and may require surgery, hospital officials said at a press conference.
The sixth grader removed a handgun from her backpack and began firing just after 9 a.m., the Jefferson County Sheriff’s Office said at the press conference. Two people were shot in a school hallway, before she moved outside and another person was shot, the sheriff’s office said.
A teacher disarmed the girl and held her until police arrived.
Once its investigation is complete, Jefferson County Prosecuting Attorney Mark Taylor told reporters his office will be filing “appropriate” charges, possibly including three counts of attempted murder.
MORE: Fired worker returned to restaurant with gun, allegedly killed 2 employees: Sheriff
A motive for the shooting is still under investigation, authorities said. The sheriff said he did not know where the student obtained the handgun.
“This is the worst nightmare a school district could ever face,” Superintendent Chad Martin said at the press conference. “We prepare for it, but we’re never truly ready for it.”