Naples, January 24 - A piece of a modern wall structure bordering the ancient site of Pompeii collapsed Thursday. No damage was reported to the world-famous ruins, authorities from Italy's antiquities department in Naples said. The section of wall - about two cubic meters - collapsed following recent heavy rains, which shifted some of the ground underneath the wall section, authorities explained. The UNESCO world heritage site has been plagued by repeated damage in recent years. On November 30 a stone wall collapsed following another wave of bad weather that battered Italy. The wall was in an area of the site that had been sealed off from the public for work to make it safe. After recent collapses in the past two years, there has been growing concern about Italy's ability to protect the 2,000-year-old site from further degradation and the impact of the local mafia, the Camorra.