PORTAGE, Mich. (WOOD) — An inert grenade has been returned to the Air Zoo Aerospace and Science Museum in Portage after a bomb squad was called to investigate it Tuesday.

Authorities were called around 10 a.m. to investigate after the Air Zoo’s collections manager found the hand grenade in a box of artifacts. The grenade dates back to the Guadalcanal Campaign of World War II, the museum said in a release.

It was found in the east wing of the Air Zoo’s Flight Innovation Center, where collections are kept. The building was immediately evacuated.

Derek Menchinger, the director of operations, exhibits, and collections for the Air Zoo said the response is part of the museum’s disaster protocols and done out a of an abundance of caution. He said it was likely a training grenade.

“Public Safety is on scene at the Air Zoo on a report of a found relic… explosive, believed to be a grenade,” Nick Armold, the directory the Portage Department of Public Safety told News 8 as officials were investigating.

The grenade was removed from the museum by a bomb squad. The Kalamazoo Department of Public Safety determined it was not a hazard after the grenade did not detonate.

The bomb was inert, the bomb squad said.

Officials originally said the grenade was returned, then later clarified it will be returned later.

“In my experience, these items are usually inert,” Daniel Mills, the senior deputy police/fire chief of PDPS said. “Better to be cautious though.”

No one was hurt.