A French fire brigade truck exists the Velodrome stadium in Marseille after a stage being constructed for a Madonna concert collapsed in the southern French city of Marseille killing one person and injuring six, July 16, 2009.?[Agencies]

MARSEILLE, France- A stage being constructed for a concert by pop star Madonna collapsed on Thursday, killing one worker and injuring seven others, police in the southern French city of Marseille said.

The July 19 concert at the Velodrome stadium, home to the Olympique Marseille soccer team, was immediately canceled.

"The roof of the stage caved in. It was only two-thirds finished," Maurice Di Nocera, a Marseille city official, told France Info radio.

The dead worker was a 53-year-old Frenchman. Two of the injured, an American and a British citizen, were in a serious condition, Interior Minister Brice Hortefeux said.

Marseille city hall said all the victims worked for a company called Live Nation, which was preparing the show.

Madonna was in Udine, Italy, at the time of the accident.

"I am devastated to have just received this tragic news," the singer said in a statement published on her website.

"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," she added.

The Marseille concert was part of Madonna's world "Sticky and Sweet" tour.