A five-story apartment block collapsed early Friday near the southern Italian city of Naples, and authorities were digging by hand to find anyone trapped. Firefighters said in a tweet that up to eight people may be buried in the rubble in the seaside town of Torre Annunziata, some four kilometers (three miles) from the Pompeii archaeological site. The news agency ANSA quoted witnesses as saying that there was no explosion before the collapse sometime after 6 a.m., but that a train had just passed by on adjacent train tracks. Images show the structure partially collapsed, revealing the interior of some apartments. Some 30 rescue workers were removing rubble by hand, passing it out in buckets, as firefighters on long, retractable ladders checked the stability of the section that remained intact. At one point, the digging was paused while a sniffer dog checked the scene. News reports indicated that reconstruction work was being carried out on the building before the collapse. The train line that passes Mount Vesuvius and connects Naples with such tourist sites as Pompeii and the Amalfi coast has been closed.