Yale Student Dies in Lathe Accident

Michele Dufault, Yale Undergratuate

Since this article first appeared in the New York Times, I’ve seen it brought up a number of times on blogs, on twitter, and even on Facebook. Most of the remarks made about the situation imply that she was not following proper safety procedures, or that shop safety in general was lax. I can’t say for sure if this was the case, having no knowledge of the situation beyond the Times article. The only thing we can say for certain is that this was a tragic accident. But there is one line in the article which jumped out at me as the most likely overall cause for this tragedy. (emphasis mine, below:)

On Tuesday, just weeks from graduating, she toiled late at night inside a machine shop in a chemistry lab, as she had for weeks while working on her senior thesis: investigating the possible use of liquid helium for detecting dark matter particles. Ms. Dufault, 22, was killed when her hair became caught in the lathe, whose rotating axis is used to hold materials like wood or metal being shaped.

I’m going to assume that because she was there late at night, it means she had other things to do during the day. This means that she had most likely already put in a full day of classes, studying, and labs before she went to work in the shop. Even when I was 22, a full day of school would have left me exhausted — I don’t think I’d have the energy to then go work in a machine shop. A machine shop is not the place you want to be when you’re tired. Fatigue is the single greatest hazard you have to deal with when using tools, particularly machine tools. Even when you’re clear-headed and alert, machine tools can kill you. When you’re fatigued, all your faculties — your reaction time, your senses, your clear thinking and spatial reasoning — are attenuated. You need all of these working at 100% to operate this kind of machinery. There are no exceptions.

A friend of mine is a toolmaker, and he told me a story about the first shop he ever worked in. He said there was a handwritten sign on the wall with the best shop safety advice he’s ever heard:

“If you’re tired, get the hell out!

That pretty much sums it up. If you’re tired, you’re a danger to yourself and to everyone else in the shop. Even if you’re taking all the proper safety precautions and wearing all the proper equipment, you will make mistakes if you are suffering from fatigue.

The thing to remember is that it’s ok to just walk away. In the case of this young woman, I imagine she was under a lot of pressure — she probably had a project deadline hanging over her head, and she was on a tight schedule. I can understand and sympathize with that, but really, there’s no college degree in the world that is worth your safety or your life.

So please be careful when you’re working with tools. Listen to what your body is telling you. If you feel your mind start to wander, or you start to make little mistakes, just stop. Walk away. Take a break or even call it a day.

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  1. I find this article particularly difficult to read. I’m guilty of having spent late hours alone in the lab or shop back when I was in grad school and I’ve known others who’ve done the same thing. But thankfully none of us was ever hurt.

    It’s also another reminder about the picture in this article, which I first saw yesterday and am not very happy about:


  2. I know what you mean. Never work in any kind of shop tired. On the other hand though, I’ve sometimes gotten in the shop and worked so long I was down to nothing but adrenaline. You can be tired and not realize it or feel the effects. That may have been the case here, and it is one of the saddest things I have ever heard. Such potential, just cut short and extinguished.

  3. Great advice, these things aren’t keyboards, or a computer file, there is no ctrl-z to undo what they do. It only takes one mistake to get seriously hurt. When I get tired, or start making mistakes from lack of concentration “stupid mistakes”, its time to turn off the power tools, do the stuff that doesn’t require them, take the time to clean up the work area, or just call it a day.

  4. “If you feel your mind start to wander, or you start to make little mistakes, just stop.”

    For some of us this is all day, every day.

  5. I must say I hate to read this. I spend some time behind the lathe when I was in (what is called) secondary school (in the US). I never had a serious injury, but I can imagine what a lathe does with you once it grabs your hair. In that cas you can only hope you’ll end up with a bald spot.

    Anyway: I hope this happens to no-one and I hope she’s somewhere better now!

  6. @Steve- to be fair, we don’t know what’s going on in that photo. I agree that, at first glance, it looks like she’s trying to move the saw by gripping the top of the blade, but that’s probably not the case. I’m thinking the blade got bound up in the material and she’s trying to wiggle it loose.

    As for the Yale article, it is indeed a tough read — it’s so senseless and sad. The only good thing that can come of it is that folks who hear the story remember it, and exercise caution in the future when working with these tools.

  7. Johngineer:

    I’m not concerned that much about how she’s holding the saw. It could even be just a strange pose the photographer wanted.

    It’s the long hair hanging down that bugs me.

  8. The thing that I keep thinking about is why was she allowed in the shop apparently alone at night? I am a machinist and it took 3 years (6000hrs) before I was allowed to work a shift alone. I have never been asked to work a night shift. They avoid having me work alone if possible because of my lack of experience. At first this bothered me because I thought I was plenty responsible, but now I understand its not about responsibility or being a contentious person. Its about safety becoming automatic, removing hands from places they should not be with out having to think about it, and most important learning to hit the Emergency Stop without hesitation. Don’t think. Hit the big red button.

  9. @Steve — Wow. I have to admit I didn’t even notice that before. Now it’s the only thing I can see.

    @Jared — I’ve been thinking about that too. It certainly seems odd. According to the Yale News, the school has immediately restricted open lab to periods when a monitor is present. Perhaps they should consider making this a permanent policy. The article I linked to also has comments from students which shed some more light on the machine shop safety policies.

  10. @Steve – Hard to say if the hair was also a photographer request. Many woodworking programs for young people start them out exclusively on hand tools, if this is the case here then long hair may not present a danger. Yes, a drill press is visible in the photograph, but there’s no telling if students are permitted to operate it. In short, we don’t know whether the picture indicates a potential safety problem or not, and it’s probably best not to speculate in ignorance.

    As somebody who has trained a lot of people on how to use equipment I have to say safety is a very tricky balance. If you go crazy and start telling people to tie their hair up to use a handsaw or chisel, you may think you’re instilling a better-safe-than-sorry approach to your students but more often you’re really just communicating that the safety rules are hysterical and unrealistic, which encourages people to break them when they are alone (as the young woman at Yale apparently did)

    The best thing you can do for a students’ safety is teach them to use their head and understand the forces and implicit dangers involved in every tool and every operation. Teaching that considering safety is the first step in every operation in the shop rather than just teaching individual safety techniques or rules by rote will hopefully lead to students who realize that if they can’t complete that first thinking step because they’re exhausted and not thinking clearly, then they need to walk away rather than imagining they’re safe because they’ve checked all the procedural boxes, so to speak.

    It’s summed up by the decal one of my mentors used to put on all the tools in his shop. “WARNING : THIS MACHINE HAS NO BRAIN. ENGAGE YOURS BEFORE OPERATING.”

  11. A very sad tragedy. I am reminded of a sign at the Orange Coast College machine shop that hung on the wall across from the door, so that you saw it every time you entered the shop: a big question mark with the international red-circle-and-slash across it, and below, the words “NO CONFUSION.” I wonder if it’s still there?

  12. When I read this article I just had to post some thoughts of my own. In my opinion anything and everything can be dangerous under certain circumstances this includes power tools and non-powered tools. Manufactures of tools are adding more and more safety features to their products, but many of us become accustomed to such safety and emergency stop features that we tend to forget to use our own judgement and also to use the equipment the way it is meant to be used regardless of said safety features. I have done this my self, thinking an AC line was disconnected because a power indicator is off and forgetting to use something as simple as a multimeter to determine it truly is safe to handle.

    During my second year at the college I attended, I was working on the software for a project late at night when my computer science instructor, in concerns of safety, had told me of a tragedy a few years prior where an art student suffered burns to most of her body while in outdoor welding area of the art department, I will not go into more detail about the incident because I am unaware of the entire scenario and do not wish to offend or upset anyone who may have known the student. I do know the school held an exhibit showing various pieces by the student including paintings and welded steel sculptures showing that she was very talented and familiar with the tools she had used.

    I do not wish to add more tragedy to this article, only to reinforce the idea that we should all be more respectful and careful of the tools and equipment we use, even if your a 10-year electrical engineer or machinist. There are far too many things that can contribute to accidents if one is not paying attention to what they are doing, which is much harder to do when you are already fatigued.

    Always trust your multimeter rather than a power indicator
    Always wear your safety goggles when particles/shrapnel are a result of the tool your using
    Learn how to use and where to place fire extinguishers/fire blankets/etc.
    for chemists and home PCB etchers learn to neutralize acids/bases
    Have an eye wash station near by and unobstructed
    NEVER operate/use any powered or non-powered tools while fatigued
    NEVER operate machinery on your own, ALWAYS use the buddy system

  13. I always thought that the rule around all machinery was to not have any loss fitting cloths or jewelry. I guess we need to include long hair now as well. Not a gender rule at all since there are some guys at work that have hair as long as any woman. There must be some way to secure/tie it back safely. That and nobody should be putting late nights in a machine shop alone.

  14. This should not have happened.

    She should not have been in there alone. If you get into trouble with a machine, there’s a good chance that by the time you realize it, you can’t reach the e-stop button; and if you do, there’s also a good chance that the machine is jammed, and you won’t be able to extricate yourself from it without assistance. If something has wrapped around you, or if you are bleeding, there’s a good chance that by the time somebody finds you, you’ll be dead. The school should have prevented this; having someone else there should be mandatory. For that matter, I won’t even work on a jacked-up car to change a tire or brakes without a buddy…

    She should not have had long hair in a configuration that could get caught. It should have been securely tied up, with stiff elastic restraints such that vibration and general movement of her head wouldn’t loosen the restraints.

    She should not have been working when she was tired (yes, I am assuming that she was tired; but given the circumstances, it’s not an unreasonable assumption). There is quite a bit of evidence (as well as common sense!) that indicates that drowsiness can be as bad as being drunk – not only is your reaction time impaired, so is your judgement.


    Most powered machine tools can not only pull you in by anything that catches on it (hair, shirt, etc), but they throw things as well. Mills will throw chips, and sometimes broken bits; and so can lathes, but lathes will also throw the workpiece should the chuck become at all loose and/or the bit dig in and jam. I once almost had this happen to me – had I been a few inches taller, I would have gone to the hospital (or morgue!). The guy working on the machine behind me had chucked up a 8" round chunk of PVC, perhaps a foot long or so, and was boring it out. I happened to look up from my machine just as it broke loose and sailed over my head, crashing into the far wall of the shop with a loud BANG. I got lucky that day – had it gone off a few milliseconds further into the chuck’s rotation, it would have hit the back of my head instead of the shop wall.

    Grinders are another nasty one… if they dig in, or are set down on their blade, handheld angle grinders can fly right across your midsection, slicing you wide open (much like a blow from a sword would). Bench grinders can throw the grinding wheel if it shatters (and because of their nature, they are quite brittle and prone to fracturing). Wire wheels often will throw wires that break off of the wheel while in operation – and due to the geometry and forces involved, they come off sharp-end-first, and will embed themselves into you.

    I could go on, but this is starting to resemble a thesis, instead of a comment… O.o

  15. It is tragic and easy to come up with solutions after the fact. I totally agree with not working with power tools when you are tired but having loose fitting clothing, long hair that is not tied up etc is such a dangerous thing around rotating machines. I grew up in a farming community and it was amazing how many farmers got killed each year when their clothing got caught in the PTO shafts of tractors.

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