A hand grenade was found in Waikiki on Sunday.
The incident happened just before 11 a.m. when a churchgoer at the Fort DeRussy Chapel discovered the hand grenade.
According to officials, the safety pin was still in place.
Entrances to the park were closed off while the explosive ordnance team searched the area.
Officials also found an unattended bag, but it was deemed not dangerous.
The grenade was taken to Schofield Barracks to be detonated and the all-clear was given about 3:45 p.m.
Officials do not know how the grenade got there.
The owner of Makani Kai Air says the plane that crashed off Molokai had catastrophic engine failure.
A top Hawaii official is dead following a plane crash off Molokai. Officials say state Health Director Loretta Fuddy died at the scene.
WATCH VIDEO: The Coast Guard transported three passengers to Emergency Medical Services after a plane crashed in the ocean off Kalaupapa, Molokai, on Wednesday.