Shelley George was about to go through the TSA security check at the Narita International Airport when everything started shaking.
"At first, it just felt like a little rumble," she said. "I thought it was a big airplane."
As the shaking continued - and grew stronger - she became concerned.
"I said, 'Is this normal?'" George said she asked the TSA employee. "And he said, 'No, this is a really big one.'"