The suspicious device that led to the brief lockdown at CL Smith Elementary School in San Luis Obipso on Monday morning was PVC pipe with fishing wire covering both ends, police said.
The pipe was discovered in a hallway by school staff at 8:04 a.m. Believing it could possibly be an explosive device, staff called 911.
Police and fire personnel who responded to the call also believed the device could have been an explosive, and they called out the County Bomb Task Force.
School officials started calling parents to tell them the school would be closed for the day.
At 9 a.m., a parent contacted officers at the school to say her son - who is a student at CL Smith - and some friends had been playing at the school over the weekend and may have left a piece of pipe with fishing line attached at the campus. The description the woman and her son gave matched the pipe believed to be the explosive device. Officers showed the boy the pipe, and he confirmed it was his.
The Bomb Task Force was then told not to respond to the campus, and parents were told school would resume for the day.
CL Smith Elementary School in San Luis Obispo was placed on lockdown for a short time Monday morning after a suspicious package was found.
The school is located at 1375 Balboa Street.
No other details were immediately available.
Police and fire personnel cleared the school just after 9 a.m.