Official inspections and structural safety checks have been scheduled on Monday for the neighboring buildings that have been deemed unsafe after the powerful explosion reduced a two-story building to ruble in a matter of seconds in Central Athens Friday morning. Six people, four Americans, a British man and Greek woman, were killed in the blast.
Investigators are working to establish what happened so the victims’ families can get answers about the circumstances of the tragedy. Evidence so far points to a large amount of gas accumulating in the upper part of the two-story building, leading to the explosion. According to information, a spark or the activation of an electrical switch may have provided the source of ignition.
The natural gas installation on the second floor of the building is being investigated by Fire Department experts.
At the same time, experts are examining the age of the building and the condition of the installation to determine precisely the circumstances that led to the destruction.
In addition to the building that collapsed, serious damage was recorded across a wide area of the neighborhood, affecting surrounding buildings, businesses and the Church of Agia Aikaterini.
“Both of the buildings on either side have suffered significant damage. In the building on the right, we essentially have a detachment of the masonry, which shows that this is precisely where the explosion occurred, toward the right-hand side,” said Efthymios Lekkas, President of Greece’s Earthquake Planning and Protection Organization.
It has not yet been established whether critical structural elements of the neighboring buildings have been affected.
Cleanup of construction debris at the collapsed building began Sunday. Experts and officials from the Fire Department’s Directorate for Combating Arson Crimes are investigating the cause of the deadly explosion.
On Monday, inspections are being stepped up, with large teams from the Municipality of Athens, the urban planning department and the Ministry of Culture.
A Spark Triggering the Explosion Leads as Scenario
According to the evidence available so far, the explosion occurred on the second floor, where the elderly couple lived, in the building’s only apartment with an independent natural gas supply.
“It appears that an explosion occurred on the upper floor of the building. This explosion was caused by natural gas, for which there was an installation. It could have resulted from various causes, including even turning on a light switch,” said Lekkas.
An inspection of the installation showed that the elderly couple used natural gas for heating through an energy-efficient fireplace, for hot water and for cooking.
The small boiler has not been located so far, with only the pipes found. Investigators are examining whether the kitchen was operating during the night without being properly shut off or whether there was a leak.
Meanwhile, the possibility that a spark caused the explosion is gaining ground, as the body of the elderly woman was found next to the bathroom sink.
The woman was found dead in the bathroom, while the other victims were found in their beds. Investigators are examining whether a major gas leak caused the concentration of gas to exceed 15%, creating an explosive mixture that was then ignited, possibly when the elderly woman turned on the light.
Victims’ Relatives Seek Answers
The two couples on the first floor— two brothers and their partners — had traveled from the United States for a short vacation. They had rented the apartment in the building, which operated as an Airbnb. Three of the four tourists were of Albanian descent and held U.S. citizenship.
“We are devastated. More family members will come to support us,” a relative of the victims said.
One of the couples was in Greece for their honeymoon and, according to a relative, the woman was pregnant with her first child. The four tourists were scheduled to leave for the United States on the day of the explosion.
The Foreign Ministry expressed its deepest sorrow over the loss of six people — four U.S. citizens, one British citizen and one Greek citizen — and conveyed its condolences to the victims’ families.
“My thoughts and prayers are with the families and the loved ones of those killed and injured in this horrific incident,” said U.S. Ambassador to Greece Kimberly Guilfoyle in a post on X.
I am deeply saddened to learn of the death of four American citizens in yesterday’s explosion in central Athens. My thoughts and prayers are with the families and the loved ones of those killed and injured in this horrific incident. Our hearts are with them during this difficult… pic.twitter.com/DffTSG1qEv
— Ambassador Kimberly Guilfoyle (@USAmbassadorGR) September 26, 2026
