The accident occurred at about 7:00 am when a cooling tower platform plunged to the ground, trapping an unknown number of people beneath it, state-run Xinhua news agency reported.
More than 40 people have been confirmed dead after the platform of the Fengcheng power plant's cooling tower under construction collapsed.
According to the city's safety department, there are workers still trapped at the scene. Paramedics and fire fighters have arrived.
Sixty-eight people were working on the platform at the time of the collapse, according to China's State Administration of Work Safety. More than 200 firefighters were deployed, as well as search and rescue dogs.
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Images from state broadcaster CCTV showed a pile of twisted metal and dozens of rescue workers searching for victims under the rubble.
China has a long history of industrial accidents, from factory explosions to mine collapses and there have been growing demands for more stringent safety standards.
Last year, the Chinese port city of Tianjin was rocked by two massive blasts Wednesday night, killing at least 173 people and injuring hundereds of others.
A metal dust explosion at a car parts factory in eastern China in August 2014 killed at least 75 people and injured more than 180.