Messing around with money-saving shortcuts or failing to understand basic physics can have deadly consequences when it comes to engineering structures like suspension bridges, dams, towers and even storage tanks. These 7 historic disasters killed over a thousand people between 1845 and 1940 thanks to shoddy craftsmanship or the unanticipated strain of heavy snow, large crowds and strong winds.
The Great Yarmouth Suspension Bridge Disaster, 1845
79 people, many of them young children, were killed on May 2nd 1845 when the Great Yarmouth Suspension Bridge collapsed under the weight of the crowd that had gathered to watch the stunts of one Nelson the Clown. The widely-advertised event drew people from all over England to watch the performer swim in a barrel drawn by four geese from Haven Bridge to the Suspension Bridge. Three to four hundred people rushed onto the suspension bridge to get a look at him as he passed underneath, and one of the rods gave way, spilling them all into the water. The youngest victims were just two years old.
Pemberton Mill Collapse, 1860
Considered one of the worst industrial accidents in American history, the sudden collapse of the Pemberton Mill in Massachusetts on January 10th, 1860 killed 145 workers and injured another 166. The five-story textile factory buckled and then collapsed at 5pm on a Tuesday, while everyone was still at work. Attempts to illuminate the wreckage with fire in order to rescue the injured added even more chaos to the situation in the form of rapidly spreading fire. An inquiry found that the calamity could have easily been avoided; the owners had loaded far too much heavy machinery on the upper floors of the factory in order to boost production, and the building wasn’t up to standards in the first place, with cheap and brittle iron pillars and improperly mortared bricks.
St. Mark’s Campanile Crumbles, 1902
When Venice’s famous St. Mark’s Campanile was struck by lightning, burned and damaged in earthquakes repeatedly over 500 years, it probably would have been best to scrap the whole thing and start over. Instead, they left the base intact and simply rebuilt the damaged parts, occasionally adding more height to the tower that was originally constructed sometime between 1148 and 1157. That wasn’t the greatest idea, given that the tower’s foundation consists of no more than some oak beams on a bed of clay. So it’s no big surprise that the tower finally collapsed on July 14th, 1902. A large crack formed in the morning, rising diagonally across the main corner buttress. Falling stones within the bell chamber prevented any fatalities by warning bystanders that something was amiss. A new tower, with a much sturdier iron foundation, was built in the lost tower’s image.
The Boston Molasses Disaster, 1919
Drowning in molasses isn’t exactly a pleasant way to die. On January 15th, 1919, a large tank of the sticky stuff burst in the North End neighborhood of Boston, sending a wave rushing through the streets at about 35 miles per hour. The Boston Molasses Disaster killed 21 and injured 50 (along with many animals, including horses), and for many decades afterward, residents claimed they could still smell the molasses on hot days. At the time, molasses was the standard sweetener, and was often fermented to produce alcoholic beverages. The tank was said to be poorly constructed, and witnesses claimed that when it burst, rivets shooting out of it produced a sound like a machine gun.
Knickerbocker Theater Roof Collapse, 1922
A popular movie theater in Washington D.C., the Knickerbocker Theater was packed with between 300 and 1,000 theater goers enjoying the silent comedy Get-Rich-Quick Wallingford when the roof collapsed beneath a load of snow on January 28th, 1922. A massive blizzard two days before had resulted in a significant accumulation of snow and ice, which put a tremendous strain on the structure’s flat roof. There was reportedly no warning of the collapse, like creaking or other unusual noises; it just suddenly gave way. 98 people died and 133 were injured. The collapse was blamed on a faulty design using arch girders instead of stone pillars to support the roof.
The Collapse of the St. Francis Dam, 1928
The “worst engineering disaster of the 20th century” occurred just before midnight on March 12th, 1928 when a dam 40 miles northwest of Los Angeles burst, unleashing total chaos across Ventura County and claiming the lives of nearly 600 people. The problems began with the decision to have William Mulholland, a self-taught civil engineer known for building things fast and cheap, head the project of constructing the new St. Francis Dam, which would provide water to rapidly growing Los Angeles. Cracks started appearing at the base of the dam soon after it was constructed, and on the morning of the disaster, a leak was discovered. Mulholland and his assistant decided it wasn’t a danger, declared the dam safe, and went back to LA.
The dam keeper who discovered the leak, along with his family, was among the first fatalities when the dam broke that night, unleashing a wave that started out 125 feet in height and spread to two miles wide as it traveled across the valley. It flooded a dozen towns and traveled almost 54 miles before reaching the Pacific Ocean at 5:30 am. Many victims were buried at sea, their corpses washing up on local beaches for years afterwards, and bodies were continually discovered all over the disaster area for decades. One was found as recently as 1992.
After the disaster, Mulholland resigned from his post and lived in isolation until his death 7 years later, taking full blame for the incident and never getting over his role in the deaths of so many.
The Tacoma Narrows Bridge, Washington, 1940
The original Tacoma Narrows Bridge was in operation for just over five months when it dramatically collapsed into the Puget Sound of Washington on November 7th, 1940. The third longest suspension bridge in the world at the time, it got the nickname ‘Galloping Gertie’ while still under construction due to the way it kicked and buckled in windy conditions. Thankfully, no one was killed when 40mph winds brought it down; the last person to cross the bridge managed to escape his car and crawl to the other side as the bridge was cracking, but his cocker spaniel Tubby was still inside during the collapse.
The bridge wasn’t flimsy, and at the time, engineers believed the mass of it was enough to keep it structurally sound despite wind-induced vibrations that caused half the central span to rise while the other lowered. Drivers reported seeing cars coming from the other direction rise and fall on a wave as they approached. But the high winds on the day of the collapse caused a never-before-seen twist, pumping more energy into the structure than the flexing could dissipate. The suspender cables couldn’t control the motion. The collapse has become a lasting lesson for science and engineering, boosting study in the field of bridge aerodynamics-aeroelastics to influence the designs of all long-span bridges built since.