Ambulances leave the Stade Velodrome stadium in Marseille following the stage collapse that left one dead.
Madonna says she is "devastated" about the death of a worker during stage construction for her upcoming concert in France.
A stage set collapsed on the crew setting up for Madonna's "Sticky and Sweet" stop in Marseilles, killing a 53-year-old man and injuring others, CNN reported.
Madonna expressed condolences in a written statement.
"I am devastated to have just received this tragic news," the singer 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."
Authorities are not sure what caused the Thursday afternoon accident, which buried the men in a pile of rubble.
"There were a lot of open fractures, of injuries, it was a messy sight," a rescue worker told The AFP.
Eighty firefighters rushed to the Velodrome stadium where two men (one American and one Briton) were found with severe injuries, and six men with more minor injuries.
Authorities say it could have been worse.
"Since it did not collapse right away, that allowed several people to get out, to avoid being hit," Marseille city councilman Maurice Di Nocera told The Associated Press.
Madonna's Sunday concert in Marseilles was canceled.