Wobbly skyscraper in China likely due to winds, rail lines, and warmer temps, local authorities claim

• A 72-story skyscraper in downtown Shenzhen, China, began shaking vertically earlier this week.
• Viral videos on social media showed hundreds fleeing the building following an emergency evacuation.
• Safety inspectors reportedly found the cause to be a combination of weather and underground foundation factors.

A combination of high winds, underground rail lines, and oscillating temperatures is likely responsible for shaking a 72-story building in Shenzhen, China, that sent thousands of people fleeing when it began wobbling earlier this week, according to local media reports.

The SEG Plaza, which stands nearly 100 ft high in downtown Shenzhen, began inexplicably shaking on Tuesday afternoon, prompting a mass emergency evacuation of the building.

-Hong Kong Free Press HKFP (@hkfp) May 18, 2021

Safety inspectors later found no abnormalities in the building's main structure or surrounding environment, according to the South China Morning Post, but that didn't stop the US consulate in Guangzhou from warning American citizens to avoid the building.

Authorities confirmed there were no earthquakes in the area at the time and said engineers had found the level of movement had not exceeded building code limits.

A preliminary investigation confirmed by the department of emergency management of Guangdong province found the wobbling was caused by winds, two underground transportation lines beneath the building, and warming temperatures that caused the steel to stretch, according to The Guardian.

The investigation reportedly found that the building's wobbling was not horizontal, but vertical. The department also said the 21-year-old building does not have a tuned mass damper, a device meant to prevent excessive movement, The Guardian reported.

Authorities would not say when the building would reopen, though vendors were allowed back in to gather items, local media reported. On Wednesday afternoon, two separate vendors told Jimu News that they felt the building swaying again.

Building management has denied reports of any further wobbling.