How the Boston Molasses Flood Worked

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Katie: Hello and welcome to the podcast. I'm Katie Lambert, joined by Sara Dowdy. How are you Sara?Sara: I'm great, how are you Katie?

Katie: Good. Sara: Today we're going to be talking about a story that sounds funny, but it's really not.

Katie: And to give you a little intro, some days when it's hot in Boston, even today, people claim you can smell molasses. Why would they say that Sara?Sara: Well, to tell you, we're going to have to go back to 1915 when molasses was a much more important commodity than it is today.

Katie: Right, I think the only thing I've ever used molasses for is maybe to make cookies.Sara: Pecan pie.

Katie: Yeah. So they're constructing a tank in Boston and this tank is a big deal. They've got 30 men working around the clock to build it, and it's behind schedule because there were all sorts of permits and stuff that had to be acquired. But in 1915, the Purity Distilling Company, owned by the United States Industrial Alcohol Company, was not thinking of baking cookies with their molasses. Rather, they wanted to distill it and use it to make munitions.Sara: So World War I is going on at the time, and even though the United States isn't in the war yet, they are supplying weapons, munitions. So this is a big industry.

Katie: And a lot of people are not happy about our involvement in all of this. President Woodrow Wilson gets a petition with more than a million signatures that basically sys to stop sending arms to countries that are at war. But it's already under way. We're going to get involved. And anarchists are not happy.Sara: They're setting fires, setting off bombs, making threats in New York City, D.C. Two bombs go off in Boston in 1916. So this is a very explosive time.

Katie: No pun intended - or was it? Italian anarchists in Boston's north end are on watch. People are trying to make sure they're not going to get into trouble. And that is where our molasses tank comes in.Sara: So as the war is heating up, the United States Industrial Alcohol and one of its subsidiaries, the Purity Distilling Company want to make a tank that can hold a lot of molasses.

Katie: It's a lucrative business, this munitions manufacturing.Sara: It is. And you want to have your tank near the harbor, because that's where the ships come in with the loads of molasses from Cuba and other countries, and you also want to have it near the railroad where it can be taken off to get processed and turned into grain alcohol.

Katie: But if you want such a prime piece of land, you're going to have to file all sorts of permits and spend all kinds of money to get it.Sara: So construction of this tank ends up being a pretty lengthy process. Getting these permits, building it, plus the construction isn't the best.

Katie: Well, and they're behind schedule, so they're much more willing to overlook problems than they otherwise might have been and they've got 30 men working around the clock to get this thing finished. And a man dies during destruction. There are super storms that December that end up with 20 inches of snow in Boston. The rain, sleet, and wind are so bad that two roller coasters end up completely destroyed. And the guy in charge of this project is just at his wits end. His name is Arthur Gel. And just as one example of the shortcuts he was willing to take because he was running late on his deadline, he only had six inches of water put in this tank that holds 2.5 million gallons of molasses to test for leaks. Because, you know, six inches in a 2.5 million gallon -Sara: That covers the bases, right?

Katie: Yes. And you'd really call this a hard deadline that's approaching because there's actually a shipment of molasses coming up to Boston. So the tank really needs to be done, or there's nowhere for all this molasses to go.Sara: Well, and for the water thing, he realized not only would he have to pay to tap into the municipal supply, it would have taken weeks to fill, and he doesn't have weeks. He's got days at this point.

Katie: So this tank ends up being really huge even though it's not really well constructed. Its 50 feet high, 90 feet in diameter, and it holds more than two million gallons of molasses, and remember, molasses is a lot heavier than water, so this is a big, big tank.Sara: In fact, it's so big that it's something of a neighborhood fixture. A leaky neighborhood fixture! It leaks so much that people come with cans and little buckets to scrap off the leaks from the tank to make lollipops, and the tank was painted brown to hide some of the leaks because naturally, you don't want to see a bunch of leaks in a 2.3 million gallon tank.

Katie: No. But we're going to fast forward now to 1919. Munitions manufacturing no longer the hot business to be in, but fortunately for the United States Industrial Alcohol company, there's another outlet for molasses.Sara: Because people are trying to pass prohibition, the 18th amendment, and so you want to get as much alcohol as you can made before that goes through.

Katie: So you want to make sure that your enormous molasses bin is full to the brim, weighing 26 million pounds when it's full.Sara: That's a lot of alcohol.

Katie: That's a lot of molasses.Sara: Neighbors and workmen have long reported ominous rumbling sounds coming from this tank. There was a guy who worked there who'd even go in the middle of the night to make sure the tank had not exploded, because something about it just wasn't right. But it turns out you wouldn't need to go check to see if the tank exploded. You would definitely know. And people unfortunately learned this the hard way January 15th, 1919 at 12:30 when the tank exploded.

Katie: First, there was a roar. Then, an explosion, followed by what was a machine gun, which was the steel bolts popping out of the tank. And the steel plates of the tank were torn apart and propelled in all directions. So this wasn't just a big leak; it actually exploded. And the flying plates cut the gurters of the L.Sara: And a 15 foot high, 165 foot wave races through North End at 35 miles per hour.

Katie: And it sounds ridiculous, but you have to think of this huge, fast wave of thick sludgy molasses.Sara: Millions of gallons of molasses just plummeting down.

Katie: 26 million pounds of molasses. There were fragments of metal 200 feet away, and that original shockwave from it exploded just flattened people. But as they were getting up, there was a vacuum created by everything coming back and then they just fell down again. So there's people and horses on the ground as this wave is coming. The elevated train is lifted off its rails. There are building collapsing, getting knocked off their foundations, and getting buried.Sara: Yeah, the three-story Engine 31 Firehouse is completely knocked off its foundation. Electrical poles are falling over and the wires are sparking in the molasses. And the rivets, like we said, are just shooting everywhere and bouncing off things.

Katie: People died from being asphyxiated or smothered. Some of them were crushed. There were horses shot by the police because they were stuck in the molasses and there was no way to get them out. There was a firefighter who was trapped underneath the firehouse and he was able to keep his head above the molasses for a few hours before succumbing and going under, because how do you pull someone out of a giant wave of molasses?Sara: The basements of buildings were just filled to the first floor with molasses.

Katie: And it turned out that 21 people died and 150 were injured. At least 20 horses were killed.Sara: And the rescue effort for this ends up being pretty extraordinary. The first on the scene are 116 sailors from the U.S.S. Nantucket. They're joined by Boston Police and Red Cross and some Army personnel. They set up kind of a triage unit at the hay market relief station, actually removing molasses from people's noses and mouths so they could breathe. The dead apparently looked like they were covered in heavy oil skins because they were just coated in molasses. The nurses are covered in molasses. They have it in their hair. There's molasses mixed with blood. It's just really nasty scene.

Katie: And the cleanup took months. Months and months as you can imagine.Sara: You can imagine. Just spill some molasses on your countertop. It's kind of nasty.

Katie: Try doing 2.3 million gallons of it in an entire city. So they used picks and chisels to get rid of the molasses that had hardened, and otherwise tried to cut it with sea water and sand.Sara: It turns the harbor brown until summer. This is in January. And obviously the molasses gets tracked all over the city too, so you can just imagine months of stickiness in Boston as streetcar seats have molasses, phones and trolleys. It's just everywhere.

Katie: And oddly enough, the night after the disaster when people are still cleaning, church bells start ringing because prohibition had just become law when Nebraska ratified the 18th Amendment. Sara: So only a month later, February 1919, the blame game begins. Somebody's going to have to pay for this. Boston is spending huge amounts of money. There's all these dead. Someone's going down, right?

Katie: And it turns into one of those evil corporations versus poor victimized families' kind of trial.Sara: And at first, the Chief Judge of the Boston Municipal Court holds USIA guilty of manslaughter, and the D.A. presents the evidence to a grand jury, and they think that the tanks are built shoddily, they agree to that, but they don't go as far as manslaughter. But by 1920, there've been 119 separate civil suits filed against the USIA.

Katie: And thi s trial is insane. Litigation for this takes over six years. There's something like 3,000 witnesses, 30,000 pages of testimony, 15,000 exhibits, and there are so many lawyers involved, supposedly there wasn't enough room to actually hold all of them in the court house.Sara: Well, it's a very odd sort of hearing too. The Superior Court Judge has so many lawsuits here that he consolidates the suits and appoints an auditor to hear the evidence and issue a report about liability and damages, thinking that from there, the cases could proceed to actual jury trials. He was kind of hoping it would streamline the process, but that didn't really -

Katie: With six years of litigation, I don't know about that.Sara: Things moved as slow as molasses.

Katie: And typically, as of the evil corporation, the owners claimed that it was anarchists sabotage, and Italian anarchists had come and set a bomb off in their tank and it exploded, and how could they possibly be held guilty for something these horrible America hating anarchists did.

Sara: It kind of reminds me of Sacco and Vanzetti.

Katie: It reminds me a lot of Sacco and Vanzetti.Sara: Same time as the Italian immigrant scapegoats. Similar story!

Katie: And no one thought this was particularly credible.Sara: No.

Katie: It's one of those things where you'd think they'd issue a public apology, but instead they were trying to blame it on the poor anarchists.Sara: Yeah, and they're saying that there had been threats against the tank. A bomb had been discovered at another USIA facility. But like you said, they don't have any actual proof for it.

Katie: And even then it could have been true, but it was fairly clear that that wasn't what caused this. They had a policeman on guard at the tank to keep any anarchists with ideas of explosions in their head from getting too close.Sara: Meanwhile, the plaintiffs are saying that the tank is the problem. They're showing that the material is too thin. They had an MIT professor who examined the shell and said it was too thin. There weren't enough rivets. The man in charge of construction was actually in finance, and didn't get any engineering advice on it.

Katie: That's comforting.Sara: And like we were talking about earlier, they're proving the construction was rushed and the tank wasn't tested properly.

Katie: Well, they even used a much thinner kind of steel than they'd actually said they were going to use in their permit. So they weren't even truthful when they were applying for it.Sara: So this hearing goes on for years, and eventually the auditor, Hugh Ogden, takes a whole year to review all the information he's been presented with. It ends up being the longest, most expensive civil suit in Massachusetts history.

Katie: That's insane.Sara: So Ogden ends up giving his verdict, 51 pages of it, in April 1925, holding the company liable. He said that the USIA gave no support of - no evidence to support their anarchy theory, whereas he had plenty of very convincing evidence on the shoddy construction side.

Katie: Well, and he said the factor of safety wasn't high enough in this tank, so the tank wasn't even strong enough for what they were doing with it. And because of this trial, there were regulations put in place that toughed up building regulations and specifically required that engineers certify structural plans, which I can't imagine we didn't have before then.Sara: Yeah, Boston requires that an architect or engineer actually sign off of on the plans, and they actually get filed through the city's building department. Something that it seems inconceivable that that didn't exist already, right!

Katie: With a 2.3 million gallon tank.Sara: But the 20th Century, it's just surprising.

Katie: The crazy thing is that no one still knows what made that whole tank explode. There's different theories, and one of them was that the molasses fermented, because the temperatures had gone at that time from two degrees from 42 degrees within a few days.Sara: A balmy January day.

Katie: Right, so things were warming up, and maybe that caused the problem. Or maybe because that whole shipment of new molasses was added on top and it was warmer and the old stuff was colder. Or maybe the tank was overfilled. Or maybe there was just some sort of structural defect. But we still don't know why it blew up.Sara: But even though they don't know exactly what caused it to explode then, Ogden recommended pretty generous damages for the parties involved. $6,000.00 going to the families of the deceased! $25,000.00 to the City of Boston, wh ich obviously had to pay for this huge cleanup effort. And $42,000.00 to the Boston Elevated Railway Company, which had broken gurters! Probably pricy to fix.

Katie: Because these damages are so generous, the lawyers for the USIA quickly agree to out of court settlements with even slightly higher damages, because they don't want to go through the price of a jury trial.Sara: Aside from the rumors that the smell of molasses still lingers in the North End on hot summer days, the site is a park now. It has bocce courts. So I guess they cleaned it up all right.

Katie: Maybe you should visit?Sara: This was a listener suggestion, and we read all of our reader emails, so we would love it if you would drop us a line at And you can also check out the blogs on the homepage at

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