"I'm pretty confident but my children aren't convinced, so we're having this test done," said Durmus Uygun, owner of an apartment on the fourth floor of the building.
"If it is positive, we will be able to live in peace. But who knows where we will be when the earthquake strikes? We may be at the supermarket or at our workplace, that's what scares us", loose the fifties wearing a black beret.
Since the 7,8 magnitude earthquake on February 6, which killed more than 48.000 people in Turkey and devastated entire regions, more than 140.000 residents have contacted the municipality of Istanbul to have their building tested.
Fifty teams of engineers roam the megalopolis, measuring the quality of the concrete and the diameter of the reinforcing bars. If the risk is deemed "very high", the buildings can be condemned to demolition.
The February 6 tremor occurred 800 km away, on a remote fault, but the images of the gutted cities have created psychosis in Istanbul, where nearly 100.000 buildings will collapse or be seriously damaged in the event of an earthquake. magnitude 7,5, by the municipality's own admission.
"Anything that can save"
Some southern districts of the city are located only 15 km from the North Anatolian fault, and seismologists have calculated at 47% the probability that an earthquake with a magnitude greater than 7,3 will occur near Istanbul in thirty years.
Two blocks from the Durmus Uygun building, in this deprived and densely populated neighborhood on the European side of Istanbul, Ali Nezir, a hardware store, has been selling whistles for a month to residents who fear that they will one day find themselves under the rubble.
"People are scared," said the man, in his small shop located under 12 floors of concrete.
Residents have started storing biscuits and water bottles at the foot of their beds. Others, like Durmus Uygun, have made up emergency bags containing enough to survive while waiting for help.
Ugur Erisoglu, an Istanbul wholesaler, sells for 200 Turkish liras (10 euros) small red bags specially designed for earthquakes containing lamps, survival blankets, emergency kits and neck braces, "everything that can save".
Its sales have exploded: "We were selling 1.000 a month. Since the earthquake, we have received 15.000 orders, including 8.000 for Istanbul".
"State of emergency"
The fear of the "Big One", sometimes rooted for a long time among the inhabitants who lived through the earthquake of August 1999, which caused more than 17.000 deaths in the north-west of Turkey, including a thousand in Istanbul, leads certain inhabitants to want to move.
“There is a strong demand for the northern districts of Istanbul, further from the fault line, and for individual houses,” explains Mehmet Erkek, general manager of Zingat, a real estate advertising platform.
Searches have also exploded for cities like Edirne and Kirklareli, located about 200 km northwest of Istanbul, away from potential tremors.
Nil Akat, a clinical psychologist, also receives patients "who are making very concrete plans to move from Istanbul".
"Many no longer feel safe at home. They are on high alert, always on the alert. In the street, they choose the right sidewalk in case a building collapses".
The psychologist spoke about it with colleagues: "A part (of our patients) can no longer think rationally".
For her, this fear can take hold of "everyone". "There is no age, no social class."
Çisel Aktimur had been thinking of leaving Istanbul for a long time, but the earthquake of February 6 transformed this desire into a "priority".
The 12-year-old, who lives on the XNUMXth floor of a tower, has a breathtaking view of part of the city.
She prefers not to imagine the scenes of devastation she would witness in the event of a major earthquake: "Even if nothing happens to my building, I probably won't be able to bear what I will see".