Two workers died and four others were injured when a scaffold collapsed at a construction site in Shanghai's Pudong New District on Thursday, local safety authorities said. The accident happened at 11:30 a.m. at a construction site for a new urban railway route near Luoshan Road, the Shanghai Work Safety Administration said in a press release. It said all the six workers were working on the scaffold when it collapsed. The four injured are being treated for fractures at a local hospital. Their injuries are not life-threatening, the press release said. The cause of the accident is being investigated.