While the immediate cause of the collapse Friday was the weather, it raised more questions about protecting one of the world's largest archaeological sites, the Italian news agency ANSA reported. Several walls and pillars have caved in in the last few years.
Pompeii, south of Naples, was buried by an eruption of Mount Vesuvius in 79 A.D. The city was rediscovered in 1748 and has been under continuous excavation ever since.
The new collapse occurred in a section of the city that was uncovered in the 19th century. The area is not open to the public.
Officials said none of Pompeii's famous frescoes were damaged.
Pompeii is a UNESCO World Heritage Site. Two weeks ago, the Italian government and European Union announced plans to spend 105 million euros ($136 million) on conservation.