A 23-year-old British man has died of his injuries after the collapse of a stage being built for a Madonna concert in southern France, hospitals officials said on Friday.

Charles Prow, a technician on Madonna's concert team, died in hospital overnight, the second fatality following the accident Thursday in the port city of Marseille. French officials had initially given his age as 32.

A 53-year-old French worker, Charles Criscenzo, was killed on the spot when the giant structure collapsed during the set-up for the Sunday concert, which was cancelled in the wake of the disaster.

Ten other people were injured, including an American who was hospitalised in a life-threatening condition and two others who were seriously hurt, hospital officials said on Friday, while 36 people suffered minor injuries and shock.

Madonna was scheduled to perform in the 60,000-seater Stade Velodrome after playing to a crowd of 15 000 in Paris last week, the latest stops in her almost year-long "Sticky and Sweet" world tour.

Firefighters said the roof of the giant stage became unbalanced as it was being lifted into place by four cranes, toppling one of the cranes which fell crashing onto the 60-tonne metal-and-cable structure below.

Most of the victims were technicians working on the stage set-up.

The US pop star, who was warming up for a concert in Udine, Italy, when she heard of the accident, said she was "devastated."

Madonna paid an emotional tribute to the two men as she performed in Udine later Thursday night.

Acknowledge and pay tribute

"I just want to take a moment to acknowledge and pay tribute to two people who lost their lives today," she said according to footage of the concert posted on the Internet.

"Two men lost their lives, which is a great tragedy to me," Madonna told her fans as she choked back tears.

"I feel so devastated to be in any way associated with anyone's suffering. So let's all just take a moment to say a prayer for Charles Criscenzo and Charlie Prow."

"Our hearts go out to their families and their loved ones," said the singer.

Prow's family, from the northern English city of Leeds, contacted the BBC, saying he was "a much-loved son, grandson, brother, uncle and friend".

"Charles was a happy-go-lucky guy with a big personality and he will be deeply missed," said a representative of the family.

French officials have opened an investigation for manslaughter, and experts have started interviewing some 50 workers and witnesses and studying the scene of the accident at the country's second biggest sports arena.

Post-mortem examinations were to be carried out on both the victims late on Friday and investigators are trying to determine whether the various subcontractors for concert organiser Live Nation had followed all proper safety procedures.

But Marseille prosecutors said it was still too soon to venture an explanation for the disaster, with interviews set to continue through the weekend.