According to the Marseille hospital authority, a second person has died after the roof of a stage being built for an upcoming Madonna concert collapsed. The British worker died Friday from injuries suffered in the accident.

A French worker was killed instantly on Thursday when the roof fell apart on top of several workers. Eight others were injured, including an American who is currently in serious condition. None of the victims' identities have yet been revealed.

The cause of the roof collapse is not yet known. Police suspect that a faulty power winch may be partially to blame.

Madonna cancelled the performance after the accident.