The Plaka district, a knot of narrow streets beneath the Acropolis where Athens receives much of its tourist trade, was the scene of a deadly disaster on Friday morning. An explosion shortly after 7.30am brought down a building in the historic centre of the Greek capital; six people died. Rescue workers recovered the last of the bodies on Saturday, after hours of searching through the rubble.

The dead, according to Euronews, appear to fall into two groups. Four American tourists had been staying on the first floor of the building. The second floor was home to a couple: a 78-year-old British man and a 77-year-old Greek woman. Greek state broadcaster ERT and other local media reported that documents and belongings found with four of the six victims, two men and two women, indicated that they were United States citizens. The process of formally identifying the bodies was still under way.

The blast also injured others and damaged neighbouring properties and vehicles. Two women were freed from a nearby building on Friday and taken to hospital, local authorities said; another person suffered minor injuries from flying debris. Buildings in the area were evacuated as a precaution.

The search was by the usual grim standards a considerable operation. Around 30 firefighters took part, with six vehicles and three specially trained dogs. Rescue teams used geophones, which listens for sounds beneath rubble, and specialist cameras to probe for voids where survivors might be trapped. Fire crews began winding the operation down after hours of work, once it became clear there was no one left to find.

What caused the explosion remains unknown. Initial reports described it as a suspected gas leak; euronews reported that the fire service, police and medical crews remained at the scene, joined by investigators from the Arson Crimes Division, which probes explosions and suspicious fires. Until that inquiry concludes, the cause is an open question, and the authorities are saying nothing firmer.

For Greece the timing could hardly be worse. Tourism is one of the country’s economic mainstays, and Plaka, a short walk from the Parthenon, is among its most visited quarters. A blast that kills four foreign holidaymakers will raise uncomfortable questions about the safety of older buildings pressed into use as lodgings, regardless of what investigators eventually determine. The answers will take longer than the rescue did.