The SEG Plaza in Shenzhen began to shake around 12:30 p.m. local time. Some 15,000 people were inside, according to the official newspaper of the Shenzhen Municipal Communist Party Committee. All those inside were evacuated within 90 minutes, local authorities said. Authorities investigating the cause of the shake said in a statement that no "abnormalities in the main structure and surrounding environment of the building" had been found.
The city's meteorological station reported a maximum wind speed of around 20 mph (32 kph) at midday Tuesday -- a rate of motion described as a "fresh breeze" by the US National Weather Service.