A gas explosion destroyed a two-storey building in central Athens on September 25, killing six people including four American tourists, Greek officials said. The blast hit Lysikratous Street in the historic Plaka district just after 7:30 a.m. on Friday. Athens Mayor Haris Doukas said the explosion likely followed a major gas leak. Officials found a failure in the building’s internal gas network, not the external network, the deputy mayor for civil protection said. The four Americans, two men and two women believed to be two couples, were due to check out and catch a 3 p.m. flight but never arrived. An elderly British man and his Greek wife also died in the collapse. Three other people were injured as the blast damaged nearby homes, shops and cars. Fire crews and rescue dogs spent more than 24 hours combing the rubble before all six bodies were recovered. The U.S. ambassador to Greece, Kimberly Guilfoyle, expressed sorrow over the deaths. The investigation into the cause is continuing. Plaka sits below the Acropolis and draws large numbers of tourists each year.