On February 6, 2023, at 4:17 a.m. local time, a magnitude 7.8 earthquake struck southeastern Turkey near the city of Gaziantep. Nine hours later, a second shock of magnitude 7.7 hit 95 kilometers to the north. Within minutes, thousands of reinforced concrete buildings -- apartment blocks, hospitals, schools -- collapsed into rubble. The final death toll exceeded 50,000 people in Turkey alone, with thousands more killed across the border in Syria. It was the deadliest natural disaster in Turkey's modern history.
Eleven months earlier, on March 16, 2022, a magnitude 7.4 earthquake struck off the coast of Fukushima, Japan. Buildings shook. Train services were suspended. A few structures suffered cosmetic damage. Four people died.
The magnitudes were comparable. The geology was different but not dramatically so. The fundamental variable that separated 50,000 deaths from four was not nature. It was engineering, governance, and the political will to enforce what engineers already know.
This is the story of that difference -- and what every earthquake-prone country should learn from it.
The Physics Are Not the Mystery
Let me be clear about something at the outset: earthquakes do not kill people. Buildings kill people. This is not a metaphor. It is a structural engineering fact. In virtually every major earthquake, the overwhelming majority of casualties result from the collapse of man-made structures. The ground shaking itself is survivable. What is not survivable is being inside a poorly constructed building when that shaking causes it to pancake.
The February 2023 Turkey earthquakes generated peak ground accelerations of roughly 0.5 to 0.7g in the hardest-hit areas. These are severe but not unprecedented values. Japanese building codes require structures to withstand ground accelerations of this magnitude without collapse. The 2011 Tohoku earthquake -- magnitude 9.1, far more powerful than anything Turkey experienced -- produced peak ground accelerations exceeding 1.0g in some locations. Buildings swayed. Some cracked. Very few collapsed. The 18,000 deaths from Tohoku were overwhelmingly caused by the tsunami, not by structural failure.
The physics of seismic waves are well understood. The engineering solutions to resist them have existed for decades. The question is not whether we know how to build earthquake-resistant structures. We do. The question is whether societies choose to build them.
What Japan Did Right
Japan's seismic resilience is not an accident. It is the product of a century of iterative improvement, driven by catastrophic failures that the country chose to learn from rather than forget.
The 1923 Great Kanto earthquake destroyed much of Tokyo and Yokohama, killing over 100,000 people. It catalyzed Japan's first serious building codes. The 1948 Fukui earthquake led to the Building Standard Law of 1950. The 1968 Tokachi-Oki earthquake exposed weaknesses in reinforced concrete design, prompting major revisions. The 1978 Miyagi earthquake drove the landmark 1981 New Seismic Design Code, which fundamentally changed how buildings are engineered in Japan.
And then came Kobe.
The 1995 Great Hanshin earthquake killed 6,434 people and destroyed over 100,000 buildings in and around Kobe. Critically, the vast majority of collapsed structures were older buildings constructed before the 1981 code. Post-1981 buildings performed dramatically better. Japan's response was not to mourn and move on. It was to analyze every failure, quantify every weakness, and upgrade the code again.
The result is a seismic design philosophy built on two tiers. The first tier requires that buildings suffer no structural damage in moderate earthquakes -- the kind that might occur several times during a building's lifetime. The second tier requires that buildings not collapse in severe earthquakes -- the kind that might occur once in several hundred years. The building may be damaged beyond repair, but the occupants survive.
This two-tier approach is not unique to Japan. What is unique is the rigor with which it is enforced.
The Enforcement Gap
Turkey has building codes. This is an important and frequently misunderstood point. After the devastating 1999 Izmit earthquake, which killed over 17,000 people, Turkey adopted a seismic code that was, on paper, among the most modern in the world. The 2018 Turkish Building Earthquake Code further updated requirements to align with European standards. The engineering specifications are technically sound.
The problem was never the code. The problem was enforcement.
In the aftermath of the 2023 earthquakes, forensic engineering teams -- including researchers from my own institution -- examined collapsed buildings across Gaziantep, Kahramanmaras, Hatay, and Adiyaman. What we found was systematic, structural failure driven by construction practices that violated basic engineering principles.
Smooth reinforcement bars instead of deformed (ribbed) bars, which provide critical grip between steel and concrete. Insufficient stirrup spacing in columns, sometimes exceeding 30 centimeters where the code specified no more than 10. Concrete that crumbled in your hand -- compressive strengths as low as 8 to 10 megapascals in samples that should have been at least 25. Columns that were too small for the loads they carried. Beam-column joints with no confinement reinforcement at all.
These were not subtle engineering failures. They were gross, obvious violations that any competent inspector should have caught. Many of the collapsed buildings had been constructed during Turkey's massive urbanization boom of the 1990s and 2000s, when construction outpaced inspection capacity by orders of magnitude.
In Japan, building inspection is a multi-stage process. Plans are reviewed by qualified structural engineers before construction begins. Inspections occur at foundation, framing, and completion stages. Third-party review is required for buildings above certain height thresholds. The system is not perfect -- no system is -- but it creates multiple checkpoints where dangerous shortcuts would be caught.
In Turkey, the inspection regime existed in law but was overwhelmed in practice. Municipal building inspectors were understaffed, underpaid, and in many documented cases, subject to political pressure to approve projects quickly. The construction amnesty programs -- which allowed illegally constructed buildings to be retroactively legalized in exchange for a fee -- were perhaps the most damaging policy of all.
The Corruption Variable
There is no polite way to discuss this. Corruption in the construction sector was a significant contributing factor to the death toll in Turkey.
Between 2004 and 2023, Turkey implemented multiple rounds of construction amnesty, most recently in 2018, when an estimated 13 million applications were filed to legalize buildings that had been constructed without proper permits or inspections. The fee was modest. The structural assessment was minimal or nonexistent. Buildings that should have been demolished or retrofitted were instead given a legal stamp of approval.
Several contractors whose buildings collapsed in 2023 were subsequently arrested. Forensic analysis of their projects revealed that they had substituted lower-grade steel, reduced concrete quality, and eliminated structural elements specified in the approved plans. The cost savings were substantial. The consequences were measured in human lives.
Japan is not free of construction scandals. The 2005 Aneha scandal, in which a structural engineer was found to have falsified earthquake resistance data for dozens of hotels and apartment buildings, shook public confidence. But the response was swift: buildings were inspected, condemned where necessary, the engineer was prosecuted, and the inspection system was tightened. The scandal led to the 2007 revision of the Building Standards Law, which introduced stricter third-party review requirements.
The difference is systemic accountability. In Japan, a building collapse is treated as a failure of the entire system -- not just the builder, but the inspector, the reviewer, and the regulatory framework. In Turkey, accountability was fragmented, delayed, and in many cases, politicized.
Early Warning: Seconds That Save Lives
Japan's earthquake early warning system, operated by the Japan Meteorological Agency, is among the most sophisticated on earth. When seismic sensors detect P-waves -- the faster-traveling but less destructive primary waves that precede the damaging S-waves -- the system broadcasts alerts to mobile phones, television stations, and industrial control systems within seconds.
The warning time varies depending on distance from the epicenter. In the 2011 Tohoku earthquake, residents of Tokyo received approximately 60 seconds of warning before the strongest shaking arrived. Sixty seconds is enough time to stop trains, shut down gas lines, open fire station doors, and allow people to take cover.
Turkey had no comparable system in 2023. The country has since begun developing one, but the 2023 earthquakes struck without any advance warning. People were asleep in their beds at 4:17 in the morning. They had no time to react.
Early warning systems do not prevent building collapse. But they reduce casualties in other ways: fewer people are caught in collapsing stairwells if they are already outside or under furniture. Industrial accidents -- gas explosions, chemical spills -- are reduced when automated shutdown protocols activate. Emergency response mobilization begins seconds rather than minutes after the event.
The cost of Japan's early warning system is approximately $500 million in infrastructure investment plus ongoing operational costs. For a country with Turkey's GDP, a comparable system would represent a fraction of a percent of annual spending. The return on investment, measured in lives saved, is extraordinary.
Retrofitting: The Unfinished Business
Even Japan has not solved the problem of its existing building stock. An estimated 9 million structures in Japan were built before the 1981 seismic code revision. Many of these older buildings remain occupied, particularly in dense urban areas where replacement is economically and logistically difficult.
Japan has addressed this through subsidized retrofitting programs. The 1995 Act on Promotion of Seismic Retrofitting of Buildings requires owners of large-scale buildings to assess seismic performance and report results. Government subsidies cover a portion of retrofitting costs. Progress has been steady but slow -- as of 2024, approximately 87 percent of residential buildings met current seismic standards, up from 79 percent in 2013.
Turkey's retrofitting challenge is orders of magnitude larger. In the southeastern regions affected by the 2023 earthquakes, an estimated 60 to 70 percent of the building stock was constructed before effective code enforcement began. Many of these buildings were mid-rise reinforced concrete frames -- precisely the structural type most vulnerable to the kind of ground motion experienced in February 2023.
The soft-story collapse mechanism was ubiquitous. Ground floors designed for commercial use -- with large open spans and minimal columns -- created a weak plane that failed catastrophically when lateral forces exceeded the columns' shear capacity. Building after building collapsed in the same way: the ground floor crushed, upper floors pancaking downward in sequence. Engineers call this progressive collapse. For the people inside, it was simply annihilation.
Lessons for Every Earthquake-Prone Country
The Turkey-Japan comparison is not meant to shame one nation and celebrate another. Japan has had its own catastrophic failures, and Turkey has made genuine progress in seismic engineering since 1999. The comparison is meant to illustrate a set of principles that apply universally.
First, building codes are necessary but not sufficient. A code that is not enforced is a document, not a defense. Every earthquake-prone country must invest in inspection infrastructure, train qualified inspectors, and protect them from political interference.
Second, construction amnesty programs are lethal policy. Any program that retroactively legalizes buildings without rigorous structural assessment is, in effect, a decision to accept a certain number of deaths in the next earthquake. The political convenience of amnesty is paid for in human lives.
Third, early warning systems are cost-effective investments. The technology exists, the deployment costs are modest relative to the savings, and the systems work. Countries like Mexico, Taiwan, and South Korea have demonstrated that effective early warning is not a luxury of wealthy nations.
Fourth, retrofitting existing buildings is as important as regulating new construction. The most dangerous buildings in any country are not the ones being built today -- they are the ones built decades ago under weaker codes. Subsidized retrofitting programs are expensive but they are far cheaper than post-earthquake reconstruction.
Fifth, accountability must be systemic and non-negotiable. When a building collapses in an earthquake, the investigation must trace responsibility through the entire chain: the architect, the structural engineer, the contractor, the inspector, and the regulatory authority. Where corruption is found, prosecution must follow.
The 50,000 people who died in Turkey in February 2023 did not die because of an act of nature. They died because of acts of omission -- codes not enforced, inspections not conducted, shortcuts not caught, warnings not issued. Japan has demonstrated, over a century of painful experience, that these deaths are preventable.
The knowledge exists. The technology exists. The engineering exists. What is required is the political will to treat earthquake safety not as a cost to be minimized but as a public obligation to be fulfilled.
Every earthquake-prone country on earth faces this choice. The next major earthquake will reveal which choice they made.
Jiro Hasegawa is a structural and earthquake engineering researcher. He specializes in seismic resilience, building code enforcement, and post-disaster forensic analysis. His fieldwork has taken him to earthquake-affected regions across Asia, the Middle East, and Latin America.