A Prince George's County high school freshman has been charged with taking an explosive to school after it went off unexpectedly in class.

Firefighters were called to Crossland High School in Temple Hills around 8:30 a.m. Monday for the report of a chemical explosion.

Fire spokesman Mark Brady said the 15-year-old showed other students at the bus stop an explosive device he made, but it didn't detonate. So he put it in his bag and carried it to his chemistry class, where it exploded unexpectedly.

The school had to be evacuated. There were no reported injuries.

The teen has been charged as a juvenile with manufacturing and possessing a destructive device and reckless endangerment. Investigators say the student learned how to make the explosive online, but they don't believe he meant to hurt anyone.