Depending on where you saw it from, the early morning eruptions in Louisville looked pretty impressive.
Some described the blasts as giant balls of fire that resembled flying saucers. A nearby police helicopter pilot described it as a bombing run. One man thought it felt like an earthquake, but it went on and on and on.
Friday, Feb. 13, 1981, was a particularly unlucky day for those living along several miles of sewer lines in the older districts of Louisville, Kentucky. The ground underneath them was exploding.
The spark that ignited the blasts came from a car driving under a railroad bridge, or so a subsequent investigation determined. The blasts travelled through the sewer lines, sending manhole covers flying, converting streets into craters and trenches, and sending fountains of sewage up through the streets, or straight up through the destroyed toilets of area residents.
Two miles of sewer lines were blown to bits, thousands of people lost access to both sewer and water, and much of Hill Street collapsed into the hole left by the 12-foot sewer main.
As always, fate had chosen to be cruel, and the worst damage was inflicted on a relatively poor working-class neighbourhood.
Amazingly, no one was killed, not even the two women who were driving to work at a nearby hospital when their car was flipped on its side by the first explosion.
The damage was so bad that many residents announced they were simply leaving. They packed their remaining belongings as fast as they could, desperate to get away from the rising sewage as rain fell over the following days.
What caused the entire mess?
It was an industrial accident, of course.
A nearby Ralston-Purina plant was using the explosive chemical hexane to extract oils from soybeans. The hexane was meant to be recycled, but instead leaked straight into the sewer system, where it built up in a sizeable quantity, spreading into the lines under the adjacent homes.
The hexane evaporated into an explosive gas, and the spark from the car apparently set it off.
The problems left behind by this king-sized industrial accident lasted for years. In the immediate aftermath, there was disruption to water and sewage for about 23,000 people, another 1,800-plus had to be evacuated, the National Guard was called in, and the stench was so bad, giant blocks of bathroom air freshener were set up near the holes.
They didnâ€™t do much.
The total damage was $30 million, of which Ralston-Purina would eventually pay about $18 million after a court settlement.
The firm was also sued by various government agencies and private landowners and paid out millions more.
Ralston-Purina fixed up the plant that caused the mess, then sold it off to another firm in 1984.
Itâ€™s amazing how many ways humans can find for industrial accidents to prove fatal or massively destructive. Whether itâ€™s the Bhopal disaster or the annihilation of much of the Aral Sea, we can turn any process into something dangerous and lethal. London had its famous beer flood (1814, eight dead) and Boston its molasses disaster (1919, 21 dead, 150 injured).
I fully expect that if I live long enough, I will see destructive floods of maple syrup, diet pop, and taffy.
The Louisville sewer explosions could have been worse. A very similar case took place in Guadalajara, Mexico. Gasoline leaked into sewer pipes and vapours built up for weeks. When they ignited, the blasts killed 252 people and levelled much of the downtown.