A hand grenade was found in a parking structure at Fashion Island Thursday morning, Newport Beach police said.

At about 7:34 a.m., Fashion Island security patrolling the parking structure between Bloomingdales and Nordstrom found a pineapple-shaped grenade standing upright in a parking stall on the second level.

"It was obviously placed there. For what reason, we don't know," said Newport Beach Sgt. Steve Burdette. "There's no rhyme or reason."

Security closed the building while authorities responded. A robot from the Orange County Sheriff's bomb squad investigated the grenade and found that the bottom had been drilled out.

There was still a pin in the grenade that meant it could still be explosive, but because the bottom had been drilled out, it would not blast out fragments as it was designed to, Burdette said.

[Updated at 11:25 a.m.: The device was determined to be inert, police said.]

Police said there were no security cameras in the area where the grenade was found. Police have no witnesses or leads.

The structure was nearly empty when the grenade was found and no one was injured.

-- Joseph Serna for the Daily Pilot