Madonna leaves the Marseille Marignane Airport in southern France. Her Marseille concert was cancelled after a stage collapse during construction killed two workers and injured eight. (Claude Paris/Associated Press)

Pop star Madonna visited Sunday with some of the eight workers injured in Thursday's stage collapse in Marseille, as well as family of one of the two men killed.

The workers had been constructing the stage for Madonna's concert, which was set to take place Sunday. The show was cancelled after the incident.

Frenchman Charles Criscenzo, 52, was killed when the roof of the concert stage he was assembling at the Velodrome Stadium collapsed. A British worker, Charles Prow, 23, died from his injuries Friday. Eight others were injured, five seriously.

In a statement released last week, Madonna said, "My prayers go out to those who were injured and their families along with my deepest sympathy to all those affected by this heartbreaking news."

Marseille Mayor Jean-Claude Gaudin spoke to reporters outside one hospital. "We are very touched that an actress [and musician] with such talent and quality has also an extraordinary amount of human qualities as well."

"She has already gone to Aix-en-Provence, I think, to see the family of this worker who unfortunately has died. And, she comes here to the hospital in Marseille to meet the injured. So, we are very touched," Gaudin said.

A criminal investigation has been launched into the two deaths. The cause of the roof collapse is still unknown.

Madonna's Sticky and Sweet tour will resume July 21 in Barcelona.

With files from The Associated Press