Crews were digging mostly by hand to search for seven people reported missing in the residential building in the seaside town of Torre Annunziata, four kilometers (three miles) from the Pompeii archaeological site.
The cause of the yesterday's collapse remained unknown, but authorities were investigating whether it was related to renovation work in the building that stood near a passenger rail line.
Officials had said seven people, including two children, from two families were missing. An elderly resident who had been believed to be inside was later accounted for.
Images show the structure partially collapsed, revealing the interiors of some apartments. Some 80 rescue workers were passing hand-dug rubble out in buckets, as firefighters on long, retractable ladders checked the stability of the section that remained intact.
More From This Section
Firefighters asked for silence among onlookers during the search in hope of hearing survivors, and the work was paused periodically to allow sniffer dogs to check the scene.
The train line that passes Mount Vesuvius and connects Naples with such tourist sites as Pompeii and the Amalfi coast was temporarily closed after the collapse.