POMPEII, Italy Is Pompeii crumbling? So it would seem, judging from the media maelstrom about several recent collapses at the ancient ruins here, including that of the Schola Armaturarum, a spacious hall used by a military association before it was engulfed with the rest of the city by the eruption of Mount Vesuvius in A.D. 79. A long tract on the north side of the Via dell'Abbondanza a commercial hub of this formerly prosperous Roman city is blocked by metal barriers, and some buildings are propped up with scaffolding as a precautionary measure. Rubble sits on the road where the Schola Armaturarum stood, a remnant of the 1947 restoration that shored up the building after it was damaged by Allied bombing during World War II. The collapses at Pompeii have become a metaphor for Italy's political instability and its inability to care for its cultural heritage. There have been calls for the resignation of the culture minister, Sandro Bondi, and investigators are beginning to address questions about the management of recent restoration efforts. The United Nations Educational, Scientific and Cultural Organization, or Unesco, sent a team of experts this month to examine the damage at Pompeii, a World Heritage site, and the findings are to be presented at a conference in June in Bahrain. "Pompeii is fragile," said Pietro Giovanni Guzzo, an archaeologist who supervised the site for the Culture Ministry from 1994 to 2009. "There's the type of construction, the shock of Vesuvius, the fact that it was buried for centuries in acidy terrain that ate away at the mortar." The pounding rains that soaked parts of Italy this fall were also a factor, he said, though far from the only one. "The rain merely drew attention to a state of neglect that has dragged on for years," Mr. Guzzo said. "Ordinary maintenance and programmed conservation are not carried out at Pompeii. That is the problem." Modern excavation of the ruins began in 1748. After that, the elements and tourism began to take their toll. Because maintenance of the 109-acre site (50 more acres are underground) has always been "irregular and insufficient," Mr. Guzzo said, Pompeii suffers. "The state of preservation has decreased and will continue to decrease, always more rapidly," he said. "Collapsing walls are inevitable." Stefano De Caro, a former superintendent here and until last month the director of antiquities at the Culture Ministry, said many natural and political issues had plagued the site: the stress produced by two million or more tourists a year, drainage, unruly vegetation, concerns about the staff levels for maintenance, tension with the site's custodians and a sometimes difficult relationship with local government administrators. "Pompeii is as complicated as it gets," Mr. De Caro said. A state of emergency was declared in July 2008, and a commissioner was appointed to cut through bureaucratic red tape and reclaim the site. Two years and two commissioners later, the national government declared the emergency over. But some now say that the officials defaulted on their mandate. Prosecutors in the nearby city of Torre Annunziata have begun investigating recent work done to inspect and restore certain sites, including the Schola Armaturarum. "The collapsing walls show us how this site was managed under the commissioner: all show, little substance," said Antonio Irlando, a local architect who leads a conservation group that monitors Pompeii. "But then no one pays attention to you if you're carrying out a census of mundane houses." Several things were done. New metal fencing with a "PompeiViva" (Pompeii Alive) logo went up along major streets at the site. Some buildings were opened, including two ancient houses that now offer elaborate multimedia programs. Yet other projects have fallen short. An adopt-a-dog program intended to address the site's stray population ended abruptly, and dogs are straggling in again. A new bike service functions only sporadically, and the opening of a new visitors' center has been postponed. Most controversially, a significant renovation of the first-century B.C. amphitheater to host concerts in the warm months prompted some experts to challenge how the restoration was carried out. Others questioned how the money was spent. "They identified emergencies that had nothing to do with the real problems of Pompeii," said Ciro Mariano, a union leader and custodian at the ruins. "They didn't need a commissioner, extra staff and a state of emergency" to contend with illegal guides or stray dogs. Meanwhile, he added, "the real emergencies continued." Archaeologists and other experts generally agree that routine monitoring is important to long-term preservation. Over the years Pompeii's topography and general state of health have been evaluated several times, most recently through a project sponsored by the World Monuments Fund. A team of archaeologists, architects and information technology experts drafted a diagnostic program and created a master plan for mapping the ruins. They also recommended steps to maintain the site. "It was a useful tool, a good foundation, but only as long as it was kept up to date," said Giovanni Longobardi, an architecture professor at Roma Tre University who helped design the project, which examined wall surfaces, paintings, plaster, floors and protective coverings. "It assisted the people who managed the site to make the best decisions they could." The work abruptly ended in 2006 after its financing was not renewed. Now, about 30 percent of Pompeii is considered adequately secured, and Mr. Guzzo said it would take about 260 million euros (roughly 348 million) to safeguard the excavated ancient city. A 1997 law granted Pompeii fiscal independence, and the site generates about 20 million euros a year from ticket sales and other proceeds. There's simply never enough money to go around. That said, collapses are hard to predict. "But the more you care for the site," Mr. Guzzo said, "the more you reduce the danger."