Four workers died Sunday after a scaffold collapsed at a construction site in Shanghai, local authorities said.

The accident occurred at about 4:07 p.m. when workers were renovating an elevator hoist way in a building at an electric company in the Xuhui District, said a spokesman with the Shanghai Municipal Work Safety Administration.

The four people were working at the fifth floor and plummeted to the ground after the collapse, the spokesman said.

They were rushed to the Shanghai Municipal No. 6 People's Hospital but died after emergency treatment, he said.

The cause of the collapse is being investigated.

(Xinhua News Agency April 20, 2009)