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Tough lessonsThings don't always work the way they were intended to work. Sometimes those failures are almost imperceptible as they build incrementally, and other times, they happen in a terrible, overwhelming instant.
"You could argue, legitimately, that engineering is the study of failure, or at least consideration of ways to avoid it," said Benjamin Gross, the Associate Vice President for Collections at the Linda Hall Library in Kansas City, Missouri, which specializes in science, engineering and technology.
These catastrophes are reminders that "engineering is a human activity," Gross told Live Science. "Disasters of this sort aren't just based around the technologies."
And so, when calamity strikes, people often ask three questions: "What went wrong? Who's to blame? What could have been done differently?" Gross said. Given the complexity of modern engineering projects, answers can be hard to find, but they may influence and improve the next attempts to cross the great expanses.
Here are 10 of the worst engineering disasters in U.S. history.
Hyatt Regency walkway collapse (1981)Slide 2 of 21
Hyatt Regency walkway collapse (1981)On July 1, 1980, the newly constructed Hyatt Regency Hotel in Kansas City, Missouri, opened to the public. The hotel featured several suspended walkways crossing its multistory atrium. Preliminary plans called for the fourth-floor walkway to hang from the ceiling, connected by steel rods. In that design, the rods would barely hold the weight of the walkway itself, and would not have passed local building codes. Those supports were included in the final construction, and to make matters worse, the second-floor walkway was suspended from the fourth-floor walkway directly above it, doubling the load on those parts.
On July 17, 1981, the hotel was crowded for a dance. The linked walkways crashed to the dancefloor, killing 114 people and injuring another 200 revelers. The structural engineer in charge of the walkways blamed the design flaw on a breakdown in communication, but the Hyatt Regency walkway collapse has become a popular case study in the ethics of engineering.Slide 3 of 21
Johnstown Flood (1889)Slide 4 of 21
Johnstown Flood (1889)
On May 31, 1889, the South Fork Dam broke, unleashing 20 million tons of water from the artificial Lake Conemaugh. The city of Johnstown, Pennsylvania was 14 miles (23 kilometers) down the Conemaugh River, and the waters destroyed 4 square miles (10 square kilometers) of the city's downtown. In total, the flood killed 2,209 people, and bodies were later found as far away as Cincinnati.
The dam was owned by the South Fork Fishing and Hunting Club, which counted many of Pittsburgh's financial elite among its members. In the aftermath, the tragedy was publicly blamed on the club's failure to properly maintain the dam, but courts maintained it was an "act of God."Slide 5 of 21
Space Shuttle Challenger (1986)Slide 6 of 21
Space Shuttle Challenger (1986)
The 25th flight of the space shuttle Challenger, STS-51L lasted just 73 seconds on Jan. 28, 1986. Shortly after liftoff, smoke briefly appeared at a joint on the right rocket booster. After a minute, flames appeared near the same location and spread. Seventy-two seconds after launch, the shuttle was obscured by white smoke, followed by an explosive fireball. The seven crewmembers aboard Challenger were killed.
An investigation into the accident, the Rogers Commission Report, determined that the O-rings used in a joint seal on the rockets were inappropriate for the ambient temperature at the time of launch: 36 degrees Fahrenheit (2.2 degrees Celsius). In the cold, the rings reacted differently to the compressive forces of liftoff. The commission found that some engineers were aware of the issue, and had advised against launches in ambient air temperatures below 53 degrees Fahrenheit (12 degrees Celsius).Slide 7 of 21
Tacoma Narrows Bridge (1940)Slide 8 of 21