Shenzhen, China - Shenzhen's Emergency Management Bureau is investigating the violent shaking that occurred despite no earthquakes being registered in the vicinity.

Building engineers are left scratching their heads as to what caused the 76-story SEG Plaza tower in Shenzhen to suddenly start shaking on Wednesday.

Seismologists reported no nearby earthquake activity, nor were there any documented strong wind gusts. A New York Times journalist based in nearby Hong Kong tweeted that there are reports the building "tilted on its foundations."

Standing at over 1,100 feet tall when the antenna height is included, the SEG Plaza is just over 20 years old, having broken records with its rapid construction in the late '90s.

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The skyscraper is mostly used as for business offices, with a multi-story electronics mall at the bottom, and four floors underground for parking.

Locals took to Twitter to share that the shaking was enough to make people sick, and videos show the antennas at the top swaying precariously.

Commenters speculate that the foundation was poorly laid, or that the building might be falling into an underground subway tunnel.

China famously puts up skyscrapers at record rates, as its massive population fuels demand. The combination of speed as well as the sheer volume of construction projects can leave room for error.

In 2020, a hotel in Fujian Province collapsed after the owner added extra stories to the building without any checks or oversight.

Bloomberg reported as far back as 2013 that various Chinese construction companies were under investigation for using cheaper, corrosive sea sand in their concrete mixtures. The prediction was that steel in these structures would be corroded after a few decades, causing the buildings to collapse.