Travelers were evacuated Wednesday morning at Ontario Airport after authorities found what turned out to be a replica grenade in a passenger's carry-on bag.
The item was initially investigated as a "possible explosive" device, leading airport police to move travelers out of Terminal 4.
The evacuation ordered at about 6 a.m. was lifted about 30 minutes later. Passengers in the lobby were evacuated outside the building. Travelers already cleared through security were sent to a gate away from the site of the investigation.
A traveler told NBC4 she saw authorities respond to the passenger screening area and one person was in custody.
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"It was very orderly, nobody seemed to be panicking," said Stabile. "We saw a man sitting in a chair with his hands cuffed behind his back."
TSA Spokesman Nico Melendez said the item was a replica grenade,which was not permitted in a carry-on bag.
Ontario Airport is about 40 miles east of downtown Los Angeles.