1.012 million buildings across three cities at high risk of earthquakes

Recent catastrophic earthquakes in Venezuela, Japan, Colombia, Indonesia, and Nepal have raised concerns worldwide. . Bangladesh is also at high risk because it lies near the junction of the active Indian, Eurasian and Myanmar plates, with major plate boundaries close to its borders.

Nearly 600,000 buildings buildings ranging from 4 to 30 stories in Dhaka city are at high risk of earthquakes. In Chattogram, according to the Chittagong Development Authority (CDA), out of 382,111 buildings in the port city of Chittagong, 278,005 are single-story, 90,444 are two-to-five-story, 13,135 are 6-to-10-story, and 537 are above 10 stories.

Old buildings and those constructed without following building codes are particularly vulnerable. According to the Comprehensive Disaster Management Programme (CDMP), an earthquake similar to the 1897 quake could cause 70,000 to 72,000 buildings built on good soil in Dhaka to collapse. Another 140,000 buildings in Chattogram and 30,000 in Sylhet are feared to collapse.

Geologists and engineers warning: Due to its geographical location, a powerful earthquake with a magnitude of 7 to 7.5 could strike Bangladesh at any time. Under such circumstances, various studies have highlighted the risk of around 72,000 buildings collapsing in the capital city of Dhaka and 300,000 to 400,000 casualties.

RAJUK lacks a comprehensive list of vulnerable buildings in the capital. The actual status of unauthorized high-rise buildings remains unclear. while unplanned construction, narrow roads, high population density, and weak infrastructure across the city could make a major disaster even more devastating. 

The Fire Service has kept a 50-member specialised Urban Search and Rescue (USAR) team ready in Purbachal, while special rescue teams have been prepared at the divisional level. RAJUK has also announced that a full survey of unauthorised buildings above six storeys will begin soon.

A survey conducted under the Capital Development Authority (RAJUK)'s Urban Resilience Project published a list of 42 vulnerable buildings. However, those were buildings belonging to various police stations, hospitals, and a few schools and universities. 

RAJUK has taken an initiative to amend the Bangladesh National Building Code, 2025 by adding a clause. Unauthorized buildings in Dhaka city will be classified into several categories to issue necessary guidelines. Among them, buildings constructed without RAJUK's approval and in violation of the Bangladesh National Building Code (BNBC) that have major deviations will be declared highly vulnerable and ordered to be demolished. Buildings with minor flaws that can be corrected will be granted approval upon paying a specified fine once the new regulations are approved.

RAJUK Chief Urban Planner Ashraful Islam said, "Rules are being amended to bring buildings that did not follow the BNBC code and lack RAJUK approval under regulation. Very soon, if the ministry approves this, a survey of all unauthorized buildings above 6 stories will be conducted. Those that are found to be highly vulnerable will be demolished. A visible full-scale survey of all unauthorized buildings will be conducted, revealing which ones are at higher risk and which are at lower risk."

According to experts, Bangladesh remains at risk of a large-magnitude earthquake due to its geographical location. Based on the earthquake cycle, a magnitude-7 or 7.5 earthquake could strike at any time. If an earthquake of this magnitude strikes Dhaka, around 72,000 buildings are feared to collapse, potentially resulting in 300,000 to 400,000 deaths.

Recent earthquakes in other countries have also highlighted the potential scale of destruction. On June 24, twin earthquakes of magnitude 7.2 and 7.5 struck Venezuela's capital, Caracas, killing nearly 1,500 people.

On August 13, a powerful 7.4-magnitude earthquake struck western Colombia. Rescue operations were still underway for people trapped under the rubble, with 270 people reported dead and 496 missing.

Professor Mehedi Ahmed Ansary of the Department of Civil Engineering at Bangladesh University of Engineering and Technology (BUET) said Bangladesh's geographical location means a major earthquake could strike at any time.

He said the country has an earthquake cycle, or return period, for magnitude-8 earthquakes that generally recurs every 300 to 350 years. Major earthquakes occurred in Arakan in 1762, with a magnitude of around 8 or higher, and on the Dauki Fault in 1897, with a magnitude of 8.1.

“However, the alarming matter is that an earthquake of magnitude 7 or 7.5 could strike at any moment,” he said.

A survey by JICA and CDMP revealed that if a 7-magnitude earthquake occurs in Dhaka, around 72,000 buildings could collapse. However, which specific 72,000 buildings these are has not been identified. 

According to the latest data from the Detailed Area Plan (DAP) formulated by RAJUK, there are approximately 2.1 million total habitable structures in Dhaka. Among them, 1.5 million are small buildings. This statistic dates back to 2022. Currently, it is learned that there are around 2.5 to 3 million buildings.

Tin-shed structures or slums pose a lower risk of massive loss of life if they collapse. However, there are over 600,000 high-rise concrete structures (above 4 stories), 40 percent of which are vulnerable.

An official from RAJUK’s Development Control Division, speaking on condition of anonymity, stated that RAJUK does not conduct assessments or evaluations of vulnerable buildings on its own initiative. A survey was conducted under JICA's Urban Resilience Project.

He said RAJUK generally inspects buildings when they develop cracks or show signs of tilting. Beyond this, there is no active comprehensive assessment of Dhaka's buildings, he added.

Several active fault lines exist around Bangladesh. The Dauki Fault, stretching about 72 kilometres from Mymensingh through Sylhet to the Indian border, is considered particularly dangerous. Plate Boundary-1, or the Arakan Fault, Plate Boundary-2 from Noakhali to Sylhet, and Plate Boundary-3 from Sylhet to Cachar also form part of the region's high-risk fault system.

Lieutenant Colonel Md. Mahmudul Hasan, Director (Operations and Maintenance) of Bangladesh Fire Service and Civil Defense, stated that a 50-member specialized rescue team has been kept ready in Purbachal to tackle major disasters, trained specifically in handling large building collapses and urban search and rescue (USAR) operations. 

The team is trained to respond to large building collapses and conduct urban search and rescue operations. Rescue equipment has also been decentralised and stored in containers in open areas in Dhaka and elsewhere to ensure operations can continue even if fire stations are damaged.

The Fire Service has also formed a 20-member Special Rescue Team (SRT) in each division.

Experts warn that a severe earthquake could disrupt Dhaka's entire transport network, while damage to infrastructure such as the Metro Rail and Elevated Expressway could make it difficult for rescue teams and equipment to reach affected areas.

Old Dhaka faces additional risks because of its ageing buildings and narrow streets, which could prevent rescue vehicles from reaching collapsed structures. Power and water supply systems could also fail, while the collapse of high-rise buildings could make nearby open grounds unusable for emergency operations.