A second-grade student was injured after accidentally shooting himself inside an elementary school classroom Wednesday morning, sparking a police investigation and sending classmates into lockdown.

The 7-year-old boy suffered a gunshot wound to his hand after bringing a firearm to Freetown Elementary School in Glen Burnie, Maryland, with the accidental discharge happening around 8:30 a.m., according to WUSA9, CBS Baltimore and The Baltimore Sun.

Other students were in the classroom at the time, but no one else was injured, per the outlets.

Anne Arundel County Police said the child was holding the gun when it discharged.

Police Chief Amal Awad said a teacher quickly secured the weapon and provided aid until first responders arrived.

“None of us can imagine the terror or the fear that students experienced here this morning, and the teacher,” Awad said, per CBS Baltimore.

The child was taken to Shock Trauma with non-life-threatening injuries, according to county fire officials, CBS Baltimore reported.

Investigators are working to determine how the student obtained the gun. Detectives preliminarily believe the firearm came from the boy’s home, per CBS Baltimore.

Schools Superintendent Mark Bedell said the building was placed on hold during the incident, and students were dismissed early at 11:15 a.m., per the outlets. Crisis counselors will be on site Wednesday and Thursday, with classes expected to resume Thursday.

Police said witnesses are being interviewed as the investigation continues.