UPDATE: Buoyancy Experiment Caused Waiakea High Lockdown

***Updated at 3:59 p.m.***

A suspicious item that prompted a lockdown today at Waiakea High School turned out to be related to a school science experiment.

Department of Education spokeswoman Dara Young said the incident began when a custodian found a bottle filled with water with what looked like metal inside in a grassy area in the center of the campus on West Kawili Street.

Police were called and a lockdown was initiated for precautionary reasons, Young said.

Police removed the object, which turned out to be a type of science experiment known as a cartesian diver left by a student from a previous period.

The experiment, named for French mathematician Rene Descartes, is used to demonstrate buoyancy principles.

Young said the lockdown lasted from 11:48 a.m. to 12:24 p.m.

Liquid-filled bottles are a cause for concern for school officials, especially following the arrests in January of two Hilo High School students in connection with an explosion of a chemical bottle bomb on campus.

The students, both 16, were suspended for a week.