Ten Engineering Disasters of the Last 100 Years

The rapid advancement of engineering technologies has led to a host of breakthroughs and new products in a wide range of industries, including biomedical, manufacturing, aerospace, and energy. Along with advancements sometimes come failures, be it in design, insufficient knowledge, or under or over estimations. While sometimes catastrophic and deadly, it is important for engineers to learn from failure. Here are 10 engineering failures that shook the industry, some from early in the 20th centurry.
 

Space Shuttle Challenger

 The event: On Jan. 28, 1986, the Challenger and its seven-member crew, including the first civilian in space—middle school teacher Christa McAuliffe—cleared the launch pad in Cape Canaveral, Fla. “For the first minute or so, the launch appeared to proceed normally,” according to NASA's website. “At 73 seconds after liftoff, controllers lost all telemetry from Challenger and noticed a fireball on television screens. Stunned controllers slowly came to realize that the vehicle had suffered a major malfunction that the crew did not survive.” The space shuttle had exploded 46,000 feet above the Atlantic Ocean, killing all seven aboard.
 
Why: The Rogers Commission, a presidential commission investigating the Challenger disaster, pinned the cause on primary and secondary O-ring seals in the shuttle’s right solid rocket booster. Record-low temperatures on launch day had stiffened the rubber rings, reducing their ability to seal the joints. “Managers had cleared the launch despite unexpectedly cold temperatures overnight at Kennedy Space Center. Managers considered significant ice covering parts of the launch tower as not enough of a concern to delay the launch,” according to NASA. After liftoff, she seals failed, setting off a chain of events that led to aerodynamic forces tearing the vessel apart, the Rogers Commission found. 
 

Union Carbide toxic gas leak

The event: Late at night on Dec. 3, 1984, 40 tons of toxic methyl isocyanate gas began leaking from Union Carbide Corp.’s pesticide chemical plant in Bhopal, India. As the gas diffused through the air, it immediately began to sicken and kill nearby residents. Though the official number of deaths was listed as 2,259, in 2008 the Indian government paid compensation to family members of 3,787 victims and to 574,366 injured, according to Edward Broughton, writing in the May 2005 Environmental Health journal.
 
Why: Broughton, then a researcher at Columbia University School of Public Health, wrote “The disaster demonstrated that seemingly local problems of industrial hazards and toxic contamination are often tied to global market dynamics. The facility operated with safety equipment and procedures far below the standards found in its sister plant in West Virginia. The local government was aware of safety problems but was reticent to place heavy industrial safety and pollution control burdens because it feared the economic effects of the loss of such a large employer.” The disaster brought to light the double standard for multinational corporations operating in developing countries, Broughton wrote.
 

Chernobyl Nuclear Power Plant

The event: On April 26, 1986, the number four reactor at the Chernobyl nuclear power plant in what is now Ukraine, but then part of the U.S.S.R., exploded. The explosion killed two power plant workers and 28 people died within a few weeks of acute radiation syndrome, according to the World Nuclear Association. Around 350,000 people were evacuated and resettled following the accident.

Why: The WNA concluded the accident was caused by flawed reactor design coupled with mistakes made by operators and that it “was a direct consequence of Cold War isolation and the resulting lack of any safety culture.” During a safety test, operators triggered the shutdown, which, due to a design flaw, increased reactivity and touched off a chain of events that caused the explosion.

Hindenburg

The event: On May 6, 1937, the Hindenburg, a commercial-passenger dirigible, caught fire during an attempt to dock with its mooring mast at the Lakehust Naval Air Station in New Jersey. The rear of the vessel imploded, and the entire airship was engulfed in flames. Thirty-five of the 97 people aboard the ship were killed, as was one ground operator.

Why: Both the German Investigation Commission and the United States Commerce Department reports concluded that a leaking gas cell allowed hydrogen from the airship to mix with oxygen from the outside. Then, a spark, possibly from static electricity in the atmosphere, ignited the gas and caused the explosion. Due to the flawed design of the airship’s outer skin, atop of which the fire is believed to have started, the electricity was not evenly distributed throughout the Hindenburg, the reports found.
 

Deepwater Horizon spill

The event: On April 20, 2010, methane gas from an oil well expanded into a drilling rig operated by BP in the Gulf of Mexico. The gas ignited and exploded, and oil began spilling from the deep-water well. The rig exploded and 11 workers on the rig were killed and 17 injured. All told, 4 million barrels of oil spilled into the gulf. The well was capped July 15, 2010, though by then the spill had affected huge amounts of wildlife. It eventually resulted in more than 400,000 claims against BP.

Why: The September 2010 internal BP investigative report placed the blame on defective cement on the well and faulted BP, the rig operator, and a BP contractor. A 2011 White House commission also blamed the well’s inadequate safety system.  
 

Fukushima Daiichi Nuclear Power Plant

The event: The nuclear accident at the power plant in Fukushima, Japan, on March 11, 2011, followed the strongest earthquake Japan has experienced, which triggered a tsunami. The accident has been classified a seven on the International Nuclear Event Scale. Chernobyl was the only other nuclear accident to be classified that high, according to the WNA. Some 110,000 residents were evacuated from the communities surrounding the plant due to rising levels of ambient ionizing radiation, the WNA said.

Why: A 45-foot-high tsunami wave swept over the plant’s seawall, flooding units one to four. The emergency generators failed, power failed, the cores of unit one to three cooled, triggering nuclear meltdowns in those units, according to the WNA. The seawall was 32 feet tall (built to code, based on information from earlier tsunamis worldwide) while the height of tsunami waves reached 50 feet in the area.

Apollo 13 Space Mission

The event: The Apollo 13 mission to the moon launched on April 11, 1970. An oxygen tank in the service model exploded two days into the mission forcing the three astronauts aboard into the lunar module. Although the LM was designed to support two men on the lunar surface for two days, Mission Control in Houston communicated with the astronauts to improvise methods to support three men for four days, according to NASA. With the world transfixed, NASA engineers and the astronauts engineered a solution and returned safely to Earth on April 17.

Why: Exposed fan wires within the oxygen tank shorted, setting fire to the insulation. The pressure within the tank rose while the fire set an electrical conduit on the outside of the tank ablaze, causing the tank to explore, according to NASA.

Hyatt Regency Hotel Walkways Collapse

The event: On July 17, 1981, the Hyatt Regency Hotel in Kansas City was hosting a dance competition when two suspended walkways collapsed, killing 114 people, and injuring 200 more. Competitors had been standing and dancing on the walkway when ceiling rods that held the weight of both the second and fourth floor walkways snapped, and the walkway fell into the crowded atrium.

Why: During his investigation, architectural engineer Wayne Lischka found the builder had substantially altered the original design. The builder constructed a double-rod support system rather than the originally designed single-rod system without approval of the engineering design team. In doing so, the created support beams doubled the loading on the connector and loads the night of the dance party were too great, Lischka found. He also determined that even the single-rod system would have barely supported the load of the dancers.

Tacoma Narrows Bridge

What happened: The Tacoma Narrows Bridge crossed Puget Sound between Tacoma, Wash., and the Kitsap Peninsula. It opened July 1, 1940. Stretching a half mile, it was the third-longest suspension bridge in the world. But not for long. On Nov. 7, 1940, the bridge collapsed in 40-mile-per-hour winds. No one was killed in the collapse.

Why: A board of inquiry into the collapse found that due to the never-before-seen phenomenon of “torsional vibration mode,”  the two halves of the bridge twisted in opposite directions while the center remained motionless. The strength caused by the motion eventually surpassed the strength of the suspender cables, snapping them one by one until the remainder were unable to support the mass of the bridge.

St. Francis Dam

The event: In 1926, a concrete gravity dam in northern Los Angeles County, Calif., was constructed by the Los Angeles Department of Water and Power to help provide water to growing Los Angeles. At 185 feet tall, the dam created a large storage reservoir of water within San Fancisquito Canyon. On March 12, 1928, the dam broke in what may have been seconds, flooding the canyon and surrounding region with 12.4 billion gallons of water. No one witnessed the break. In all, more than 431 people died, most of them sleeping in communities in the water’s path.

Why: A Los Angeles City Council commission attributed the collapse to a defective foundation, as did a governor’s committee. The city council commission found the actual break came from a leak that began under the concrete. In contrast, the governor’s commission found the dam’s western hillside was of inferior strength to hold back the huge amount of water.

Jean Thilmany is an independent writer in Saint Paul, Minn.