Arroyo Grande High School was put on lockdown for about 10 minutes on Monday morning due to a triggered smoke alarm.
The lockdown was called at 11:20 a.m, according to Lucia Mar Unified School District spokeswoman Amy Jacobs. When school officials couldn't clear the alarm, they called the Five Cities Fire Authority to take care of it.
The alarm went off in a locker room restroom, according to a release from the Arroyo Grande Police Department.
The lockdown was lifted at 11:35 a.m., Jacobs said.