A student took a homemade firework device to Bethesda Chevy Chase High School Thursday morning, according to Montgomery County Public Schools.
Students found a device like a homemade M-80 in a science lab.
The classroom was evacuated and swept by a K-9. K-9 also checked nearby hallways. No other devices were found.
The student, who did not make a threat or attempt to use the device, will be disciplined, according to MCPS.
Montgomery County fire and police officials are investigating.
