Waiakea High School in Hilo was briefly locked down Thursday afternoon as police investigated a "suspicious object" that tuned out to be a school project.

A custodian found a bottle filled with water and what appeared to be metal around 11:45 a.m., according to school Principal Kelcy Koga.

Police were called and the school was placed under lockdown for about a half-hour until 12:24 p.m.

Hawaii County police and fire crews removed the device, which was later identified as a chemistry experiment that a student accidentally left behind.