Korean scientists think they have determined what caused a 39-story Seoul skyscraper to shake violently for 10 minutes, causing the building to be evacuated for two days.
Gale-force winds? Sorry.
Volcanic activity? Unh-uh.
No, the culprit, they say, was 17-middle-aged gym rats working off the midriff bulge in a Tae Bo class.
Apparently, while dancing and boxing to "The Power" by Snap on July 5, the exercisers not only shook their booties, they shook the building.