KAPOLEI (HawaiiNewsNow) - It happened around 10:00 a.m. Monday when someone placed the device in the boys room on the first floor of Building "G," that's the ninth grade building.
Authorities describe it as a chemical pressure bomb.
Ingredients are mixed together in some sort of sealed container.
A chemical reaction builds inside the container until it explodes.
No one was in the room at the time, but five school workers were exposed to fumes, and one was sent to a hospital to be checked out.
"Any time there is an improvised explosive device of any kind it is not predictable. It can cause injury and death to the person that made it and is operating it and worse it can cause the same for innocent people," HFD Capt. Terry Seelig said.
"So we want to make sure that students know, this is not fun and games. This is a very serious incident and again, we will exercise all of our authority that we can," Kapolei High School principal Elden Esmeralda said.
Late Monday afternoon two students were at the Kapolei substation being questioned by police.