A stage under construction at Velodrome stadium in Marseille, France collapsed today (7/16), killing a 53-year-old French worker and injuring six--two seriously.

According to reports, four cranes were lifting the roof of the stage when it became unbalanced. Once of the cranes toppled, falling onto the under-construction stage.

About 50 workers were said to be involved in the stage's construction, and perhaps 12 reportedly were beneath the stage when it collapsed. The stage apparently collapsed gradually, which allowed many workers to escape unharmed.

Madonna had been scheduled to perform at the 60,000-seat Velodrome Sunday (7/19). That show, part of her "Sticky and Sweet" world tour, has been canceled.

"I am devastated to have just received this tragic news," she said in a prepared statement. "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."