FLORENCE—An expert warned today that Michelangelo's David is at risk of toppling over, ANSA reports.

Antonio Borri, a structural engineering professor at Perugia University, spoke at a conference today, saying that the statue's weight, pose, and low quality of marble put it at risk. He told attendees that the world-famous sculpture could fall "not only if an earthquake hits but also because of continual environmental stressors such as building work or pneumatic drills in the street outside."

As proof, he cited the fact that cracks in the work's left ankle and carved tree stump that were plastered over in 2004 have "all already resurfaced." The cracks allegedly developed because David's ankles are too thin to support his 5,572 kg weight, and because the sculpture spent centuries in Florence's main square, leaning forward dangerously.

Borri added that the statue was not in danger of imminent collapse, except in the unlikely event of a major earthquake, but he recommended that measures be taken to stabilize the piece. Work is also under way on special equipment that will produce a CAT scan of the statue, which will help identify invisible fractures in the marble.

And Florence's other famous David statue, Donatello's earlier version in bronze, will be closed off from public view for two months starting October 1, authorities announced today. The decision comes at the beginning of the final and most delicate phase of the sculpture's restoration, which has been public since June 2007. The fully restored David will be unveiled under a new lighting system on November 28, two days before the Tuscan celebration Festa della Toscana.