Earlier this year, part of a wooden stand of spectators collapsed during a bullfight in Colombia, killing at least four people and injuring hundreds more.
In 2017, in Oroville, Calif., nearly 180,000 people were evacuated downstream from Oroville Dam--the country’s tallest dam and one of the largest earth-fill dams in the world--when the dam’s spillway failed from heavy rains, threatening to release a 30-foot wall of water into the valley below.
Crisis averted, but the event was a wake-up call for dam safety.
Historically, many structural failures can be blamed on lack of building codes. But six of the 30 deadly disasters on this list, which include the failure of dams, bridges and buildings, occurred in the 2000s, including the attacks on Sept. 11.
In tragedies like the 1995 bombing of the Alfred P. Murrah building in Oklahoma City, or the World Trade Center attacks, the cause of structural collapse might be considered to be outside the scope of engineers’ worst-case scenarios. The twin towers were built to absorb high wind loads, withstand fire long enough to evacuate the building, and even an errant aircraft that might accidentally hit one of the towers--but not to the extent of what did occur.
For structural engineers, events like Sept. 11 and the collapse of the bombed federal building in Oklahoma City are tragic, but also opportunities to learn and improve structural integrity, writes Shih-Ho Chao, an associate professor of structural engineering and applied mechanics at the University of Texas in Arlington. Engineers have since identified major ways to reduce the likelihood and severity of collapse by strengthening construction materials and improving structural design to better resist explosions, Chao writes.
This list of the worst structural failures of all time comes from researchers at ForneyVault, a machine integrated, cloud-based platform that provides construction material testing software solutions to eliminate the error-prone manual processes in construction that can lead to the deadly failure of buildings, dams or bridges. In some of these structural failures, building owners, engineers, inspectors, or even the local government were found to have cut corners during construction or inspections, which led to these catastrophic consequences, ForneyVault says.
These are the 30 deadliest structural failures of all time.
1. Fidenae Amphitheatre, Rome
- Type of structure: amphitheater
- Year: 27 C.E.
- Death toll: 20,000
The amphitheater was cheaply constructed with wood and not able to withstand the 50,000 people who came to watch the gladiator games, causing it to collapse.
Viviano Codazzi (1604-1670) and Domenico Gargiulo (1609-1675), Museo del Prado
2. Ponte das Barcas, Porto, Portugal
- Type of structure: bridge
- Year: 1809
- Death toll: 4,000
This bridge was uniquely built by connecting wooden boats together, which unfortunately collapsed under the weight of thousands of people trying to escape Portugal when the French attacked under Napoleon.
Joseph James Forrester (1809–1861)
3. World Trade Center, New York City
- Type of structure: building
- Year: 2001
- Death toll: 2,996
The Twin Towers were struck by hijacked commercial airplanes, resulting in fires that caused floors to sag and perimeter columns to buckle, ultimately leading to the collapse of both towers.
Shutterstock
Though a new One World Trade Center was built, today a memorial stands at the site of the collapsed towers.
The new One WTC is made of a hybrid concrete-and-steel structure with a massive, extremely strong concrete core and has a dedicated first-responders’ staircase that allows emergency responders to climb quickly while others evacuate, according to engineering firm WSP.
4. South Fork Dam, Johnstown, Pa.
- Type of structure: dam
- Year: 1889
- Death toll: 2,209
After days of heavy rain, the dam failed catastrophically and released 20 million tons of water.
The dam had already failed twice before. You can visit the site which is now a memorial under the National Park Service.
Shutterstock
5. Vajont Dam, Friuli Venezia Giulia, Italy
- Type of structure: dam
- Year: 1963
- Death toll: 2,000
After the government dismissed reports that part of the dam's basin was unstable, a landslide caused a mega-tsunami in the lake and sent a wave of 13 billion gallons of water over the top of the dam, destroying several villages and towns. The dam, one of the tallest in the world, is not used today.
Shutterstock
6. Eitai Bridge, Tokyo
- Type of structure: bridge
- Year: 1807
- Death toll: 1,400
Due to a dispute between people living on either side over who should pay for maintenance and repairs, the Eitai bridge was left unmaintained. A girder collapsed during a festival when thousands of people were crossing it.
Edo-Tokyo Museum
7. Rana Plaza, Savar, Dhaka, Bangladesh
- Type of structure: building
- Year: 2013
- Death toll: 1,134
When structural cracks were found in the building, the businesses on the lower floors were immediately closed. The five garment factories on the upper floors made their workers keep working, and the next day when a power outage occurred, diesel generators at the top of the building were turned on. Then the building collapsed.
Shutterstock
Relatives and survivors wait outside the hospital after the collapse of the Rana Plaza. The tragedy shone a spotlight on the underbelly of the global fashion business.
Shutterstock
8. Circus Maximus, Rome
- Type of structure: stadium
- Year: 140 C.E.
- Death toll: 1,112
The upper tier of seats in this oval-shaped chariot racing stadium collapsed under the weight of too many spectators. The remains of the stadium still exists in Rome today.
Shutterstock
9. Sampoong Department Store, Seoul, South Korea
- Type of structure: building
- Year: 1995
- Death toll: 502
During construction, the building’s use changed from residential to a department store, and multiple support columns were removed. This led to widespread cracking in the roof when heavy A/C units were moved. The owner refused to evacuate for fear of loss of revenue, and the building collapsed not long after, killing 502 people. Lee Joon, the chairman of the construction company, was eventually found guilty of criminal negligence and sentenced to prison.
Seoul Fire and Disaster Headquarters
10. St. Francis Dam, Santa Clarita, Calif.
- Type of structure: dam
- Year: 1928
- Death toll: 431
The dam was built as part of the Los Angeles water department’s massive water grab in the early 1900s under civil engineer William Mulholland. Twelve hours after Mulholland himself inspected the dam, it catastrophically failed and triggered a deadly flood. The wall of water was two miles wide. A defective soil foundation and design flaws were deemed to be the cause.
USGS/Wikipedia
11. Malpasset Dam, Cote d'Azur, France
- Type of structure: dam
- Year: 1959
- Death toll: 423
A combination of the pressure of heavy rainfall filling this dam's reservoir to its maximum level and a tectonic fault in the impermeable rock base, which had been inadequately surveyed, led to collapse. The wave of water was 130 feet high.
Shutterstock
12. Dzhrashen School, Spitak, Armenia
- Type of structure: building
- Year: 1988
- Death toll: 400
A strong earthquake led to the precast concrete floors of the school building collapsing, which was caused by poor ties with the walls. The building pictured here, in Spitak, is not identified. The earthquaked caused extensive damage in the region.
LoMit/Wikipedia
13. St. Servatius Bridge, Maastricht, Netherlands
- Type of structure: bridge
- Year: 1275
- Death toll: 400
This pedestrian bridge is one of the oldest in the Netherlands. Back in 1275, the bridge was made of wood, and it collapsed under the weight of a large procession of hundreds of people that were crossing it, killing 400.
14. New London School, New London, Texas
- Type of structure: building
- Year: 1937
- Death toll: 300
The school was heated with odorless natural gas, which leaked into a long crawlspace underneath. A spark from an electric appliance caused explosions across the entire building, and the main wing collapsed, killing 300. Pictured is the memorial.
Shutterstock
15. Val di Stava Dam, Stava, Italy
- Type of structure: dam
- Year: 1985
- Death toll: 268
The dam was poorly maintained, and after issues with drainage, water pressure forced the dam to fail and release 47 million gallons of water, sand, and mud that crashed through the village, killing 268 people, destroying 63 buildings and demolishing eight bridges.
Shutterstock
16. Dale Dike Dam, South Yorkshire, England
- Type of structure: dam
- Year: 1864
- Death toll: 244
This dam was just newly built in 1864 when it failed the day after the reservoir was filled, releasing a flood of 828 million gallons of water.
Steve F/Wikipedia
17. Angers Bridge, Angers, Maine-et-Loire, France
- Type of structure: bridge
- Year: 1850
- Death toll: 226
The failure was attributed to the dynamic load from both a storm hitting the bridge and hundreds of soldiers crossing it while walking in step, causing multiple cables to break and the bridge to partially collapse.
Wikipedia
18. Corralejas Bullring Stadium, Sincelejo, Sucre, Colombia
- Type of structure: stadium
- Year: 1980
- Death toll: 222
Sincelejo's annual festival, Fiestas del dulce nombre de Jesús, includes a structure known as Corraleja, a temporary wooden bullring, pictured here. In 1980, the hastily-constructed stands collapsed during a heavy rain when people were trying to escape the weather and the ground beneath had been reduced to mud.
Luis Pérez from Medellin, Colombia / Wikipedia
19. Dharahara, Kathmandu, Nepal
- Type of structure: building
- Year: 2015
- Death toll: 200
A magnitude 7.8 earthquake caused the 236-foot tower to collapse, killing up to 200. Only the base of it remained standing. It was the tallest structure in Nepal and has since been rebuilt.
Shutterstock
20. Alfred P. Murrah Federal Building, Oklahoma City
- Type of structure: building
- Year: 1995
- Death toll: 168
The building was the target of a bombing by Timothy McVeigh, causing one third of the structure to collapse just seconds after a truck bomb detonated. Nineteen children were among the 168 people killed.
FBI
21. Whangaehu River Rail Bridge, Tangiwai, New Zealand
- Type of structure: bridge
- Year: 1953
- Death toll: 151
The collapse of a nearby dam caused a mudflow that destroyed one of the concrete pylons of the rail bridge. The bridge then collapsed when a passenger train crossed it just minutes later. The locomotive and first six carriages derailed into the river, killing 151 people.
New Zealand Archives
22. Maddur Railway Bridge, Maddur, India
- Type of structure: bridge
- Year: 1897
- Death toll: 150
The river below this rail bridge in India had flooded from heavy rains, causing it to collapse just as a train full of passengers began to cross it.
23. Pemberton Mill, Lawrence, Massachusetts
- Type of structure: building
- Year: 1860
- Death toll: 145
The factory had not been constructed to code, and the second floor was overloaded with equipment. The building buckled and collapsed. Pictured is the rebuilt mill.
24. Royal Plaza Hotel, Nakhon Ratchasima, Thailand
- Type of structure: building
- Year: 1993
- Death toll: 137
The Royal Plaza Hotel collapsed in just seconds following the gradual deformation and weakening of the support columns; when one failed, the rest quickly did as well. It was later blamed on a violation of safety regulations by the engineer.
CSZero / Wikipedia
25. Buffalo Creek Dam, Logan County, W. Va.
- Type of structure: dam
- Year: 1972
- Death toll: 125
Four days after being inspected and declared satisfactory, this coal slurry impoundment dam failed after heavy rains and unleashed a 132-million-gallon tidal wave of black waste water. This image shows mobile homes used by families after their homes were wiped out.
Jack Corn / National Archives
26. Weiguan Jinlong, Tainan, Taiwan
- Type of structure: building
- Year: 2016
- Death toll: 116
Weiguan Jinlong was the name of a residential building that collapsed in an earthquake, killing 116 people. Later it was discovered that cooking oil cans had been used as building materials in the walls and polystyrene had been mixed into concrete in the support beams.
27. Synagogue Church of All Nations, Lagos, Nigeria
- Type of structure: building
- Year: 2014
- Death toll: 115
A guesthouse on the premise collapsed due to structural failure. Government agencies found that inadequate beams and columns and a lack of rigid zones or movement joints were to blame.
ScoutT7 / Wikipedia
28. Canterbury Television Building, Christchurch, New Zealand
- Type of structure: building
- Year: 2011
- Death toll: 115
The building collapsed in an earthquake after having been declared safe during inspections after two prior earthquakes. It was later found that the supervisor of the building’s construction had faked his engineering degree.
Michael Lucas / Wikipedia
29. Hyatt Regency Hotel, Kansas City, Mo.
- Type of structure: building
- Year: 1981
- Death toll: 114
The hotel had two walkways collapse under the weight of many people, crashing to the floor. It was later found that a change in the design of the walkways’ hanger rods led to the collapse.
Wikipedia
30. Eden Railroad Bridge, Eden, Colo.
- Type of structure: bridge
- Year: 1904
- Death toll: 111
A thunderstorm caused a flash flood wave to pass over the trestle, which caused part of the bridge to collapse and pushed half of the train into the river.
Check out an infographic and map of these disasters at ForneyVault.com.
Denver Public Library
