Two days after the launch of the Leishenshan project, 30 out of a projected 500 prefabricated buildings had arrived at the site from Suzhou in the eastern province of Jiangsu.

Chen Ye, one of the suppliers, said the remaining 470 buildings will be in place by Saturday.

"Time is life. We are racing against death," said Chen, who participated in rescue efforts after the 2008 Sichuan earthquake, which killed nearly 70,000 people. "But quality and safety are also important, as we are building medical facilities."

He said inpatient wards and intensive care units require extremely high standards of cleanliness and impermeability, and his factory in Suzhou is working around the clock to produce top-quality facilities. He has ordered 1,200 facemasks to protect the company's 15 employees who are working at the construction site.

"We are assembling most of the buildings in our factory to shorten the workers' exposure time in Wuhan. It saves time and is safer for the workers," he said."Efficiency and safety are not contradictory."