The Brooklyn Bridge is a marvelous feat of engineering.
Now one of New York City's most popular tourist attractions, the completion of the hybrid cable-supported suspension bridge in 1883 was meant as a symbolic joining of the boroughs of Manhattan and Boston. With numerous lanes to carry streetcars, elevated trains, pedestrians, bicycles, a total length of 5,989 ft (1,825.4 meters), and rising nearly 300 feet above the East River, it was hardly surprising that construction supervisor Washington Roebling called it the "most stupendous engineering structure of the age" 
After more than fifteen years of construction, the grand opening of the bridge on May 24, 1883 was a major media event. Newspapers across the country carried stories about the majestic bridge, complete with photographs, engineering details, and descriptions of the political battle that led to the bridge being approved in the first place. Naturally enough, thousands of pedestrians marked the historic occasion by crossing the bridge on foot (it likely helped that the toll for pedestrians was only one cent U.S.). Considering the breathtaking views that pedestrians and cyclists could get while on the bridge, there was no shortage of people lining up to cross.
Even after a week following the grand opening, thousands of people were still crowding onto the bridge on May 30, 1883 when something went very wrong....
Though eyewitness accounts seem to vary, the problem apparently began when a woman tripped and fell as she was descending the wooden stairs on the Manhattan end of the bridge. This, by itself, shouldn't have done more than spark mild concern. Unfortunately, it was late in the afternoon when the crowds were at their thickest. As one newspaper reported the events of the day, "strong men and feeble women, manhood and infancy were wedged together in that fearful pressure of the crowd which extended miles, one might say, on either end of the line."
It was apparently at this point that the things became particularly chaotic. Being acutely aware that they were suspended 130 feet over the water, people in the crowd became convinced that the bridge was in danger of collapsing and began pushing frantically to get back to solid ground. One woman even dangled her baby over the side of the bridge and begged someone below to take it to safety. Since the only exit was along a narrow wooden promenade, that was where the crowding was at its densest. Though some quick-thinking officials managed to cut away the iron fences that were preventing people from going over the sides of the promenade, this may have made things even worse since the fences were the only thing preventing many from falling to the street below.
What followed was a scene of carnage. One reporter covering the story likely described it better than I ever could:
"Those unfortunate to be near enough, and weak and fainting, fell helter-skelter, heels over head, down on the jagged, gravelly road beneath, a mass of bruised, discolored human flesh. Scores were trampled on instantly and to stumble was death. Men were dragged out of that heap of humanity with their faces blue as indigo, and their life blood trickling out of their nostrils. Children and women, pale, disheveled, and dead. The roadway on either side was strewn with the dead and dying, a pitiable sight, and yet it is said of the bridge officials that no efforts were made to stop people coming on the bridge. The dead and dying were carried off in wagons, carts, etc., improvised on the moment for service, and it was a long time before anything like order was restored or an ambulance appeared."
Fortunately, nearby soldiers in uniform took charge of the scene and acted as volunteer police officers to restore order and evacuate the injured. A makeshift morgue was set up at the nearby hospital on Chambers Street and all of the injured were brought there for treatment. After hearing news of the disaster, hundreds of anxious relatives swamped the hospital trying to get news about their loved ones. Newspapers wrote lurid stories describing the carnage and the life-threatening injuries many of the survivors had sustained.
Though only twelve fatalities were actually linked to the bridge disaster, hundreds of others, including men, women, and children, had injuries included crushed limbs and broken bones. But the stories spreading across New York by word-of-mouth suggested that the disaster was far greater than it actually was. One story going around for a while was that the bridge had collapsed with a death toll of over 1,000 people. While the rumours slowly subsided, there was still the question of who would be held responsible for the deaths involved.
In the months that followed the Brooklyn Bridge disaster, new safeguards were put into place to ensure greater safety for pedestrians and vehicles crossing the bridge. Also, a New York court held that same year absolved the Bridge trustees of any responsibility for the tragedy. Still, the deaths made people more apprehensive about using the bridge and, as a result, the revenue from bridge tolls were much lower that year than originally predicted. Considering that the Bridge was supposed to be self-supporting (at least in terms of maintenance costs), not to mention the expensive bonds that had been issued to help fund construction, the Bridge that had been hailed as a wonder of the modern world began to look like a financial sinkhole.
Which brings us to P.T. Barnum, master showman and inveterate promoter, who decided on a rather unique way of demonstrating the bridge's safety (not to mention drumming up enthusiasm for his circus). On May 23, 1884, Barnum marched his entire herd of elephants, twenty-three in all, including his star attraction, Jumbo, across the bridge, while hundreds of pedestrians followed. Not only was it the biggest day since the bridge's opening the year before, but it also helped end lingering fears about the Brooklyn Bridge's safety. The event proved to be so popular that Barnum would repeat the stunt in later years.
While there were far greater tragedies occurring in 1883, including the enormous loss of life following the Krakatoa eruption that same year, the Brooklyn Bridge panic is still memorable for how easily a panic can start and the often tragic consequences that can follow. It's a lesson that needs to be carefully considered in any large gathering of people and, yet, somehow, new tragedies always seem to arise.