In the past, researchers thought the important material was volcanic ash that came from the area of Pozzuoli, near Naples.

过去，研究人员认为重要的物质是来自那不勒斯附近波佐利地区的火山灰。

The Italian prime minister was among thousands of mourners at the service in a sports hall in the southern town of Pozzuoli.

葬礼在南部小镇波佐利一个体育场举行，意大利总理和数千名哀悼者一起参加。