Imagine it. You’re reversing your jetski into the water at the boat ramp, getting excited for a day of on-water escapades. Like so many before you, you mess up, your car loses traction, and slides into the drink. Only, in this tale, it doesn’t just get wet. It catches fire and burns to a cinder all while fully submerged. Let’s dig into what we think happened, and explore why the abundant seawater failed to put the fire out.
[Ed Note: Before we get into this, we should admit that the full context of this fire is still unknown (for example, we don’t know if the vehicle had been damaged in some way prior to submersion). We’ve seen a few videos floating around, some posts by organizations that appear to have expertise on these things, and that’s more or less it. Also, it’s worth mentioning that we are not trying to scare people into thinking EVs are dangerous; gasoline catches fire pretty damn quickly, as well. Still, it’s a car on fire underwater — it’s worth sharing these fascinating clips and talking about them a bit. -DT]
We’re talking about the owner of a Tesla Model X at the Polk Street Boat Ramp in Hollywood, Florida. According to Hollywood Professional Firefighters, who attended the scene, the electric vehicle slid into the salty inter-coastal waters, with the conductive water apparently causing a short circuit. The battery proceeded to catch fire, with gases bubbling up through the water and flames visible at the surface, as the pack entered thermal runaway. Thankfully, the occupants of the vehicle were able to flee the vehicle before it sank beneath the waves and caught fire.
Despite being fully submerged, the car continued to burn for an extended period of time. The fire crews attending elected to allow the car to burn itself out while still underwater, rather than attempting recovery. Once the fire ceased, the car was pulled from the water and loaded onto a carrier. A fire engine was assigned to follow the car to the impound lot out of an abundance of caution, as EV batteries have been known to spontaneously reignite after being extinguished.
https://www.facebook.com/HollywoodProfessionalFirefighters/posts/pfbid02sodTkCfmT2dhdCwNea1H9FxAAEzC9GavkqWiUkyPJjYgAzay53FMkemmPnz6B1Mrl
Here, we’ll just re-quote the post above from Hollywood Professional Firefighters, which describes itself as “a non-profit organization that represents the City of Hollywood’s Firefighters” and whose main objectives are “monitoring and improving Firefighting and Public Safety, and maintaining a cooperative labor management relationship with Hollywood’s Fire and City Administrators, Elected Officials and the City’s residents.”:
WATER RESISTANT FIRE??
On Sunday Oct 1st, a Tesla Model S was attempting to back a jet ski into the water at the Polk Street boat ramp, when it lost traction and slid into the inter-coastal. The salt water reacted with the the vehicle’s electronics causing them to short, sparking a fire that burned underwater for an extended period of time.
The fire was allowed to burn underwater until it extinguished itself. And even then, it had to be loaded carefully onto a special carrier, and followed by the Fire Engine to the impound lot, where they’ll keep the vehicle isolated for a few days in the very real possibility of re-ignition. EVs have been known to reignite even after the initial fire has been extinguished.
This is an issue with all Electric Vehicles, not just Tesla. And their prevalence is adding a whole new level of hazard to the Fire Service, causing Fire Departments worldwide to rethink how they mitigate electric vehicle emergencies.
NOTE: There’s a second bystander-submitted video in the comments section of the original post.
Nobody was harmed in the incident.
A video in the comments of that post has been reposted to popular YouTuber Rich Rebuild’s channel:
It’s worth noting that Tesla CEO Elon Musk is famously on record as saying that a Tesla “works as a boat for short periods of time,” by virtue of having no air intake or exhaust for the propulsion system, and sealed batteries, motors, and electronics. “Submarines are just underwater EVs,” he writes in that tweet:
A Tesla works as a boat for short periods of time, as an electric car has no air intake or exhaust to block & battery/motor/electronics are water-sealed. Submarines are just underwater EVs. https://t.co/1U63ZoVj3q https://t.co/KKfcUQGYnL
— Elon Musk (@elonmusk) January 25, 2020
Seeing is believing, however, and this Model X very obviously caught fire. According to a recounting from those on the scene in this YouTube video (the one above that Rich Rebuild reposted), the car apparently showed a warning to the female occupant to exit the car immediately, and she was rescued by her husband before the car sank fully beneath the water, battery aflame.
The fact that it did would be of no surprise to any experienced fire crew, as it has become well-known that EV batteries can fail in this manner when inundated with flood water or salt water. NHTSA, in its write-up “Responding to Electric Vehicle Fires Caused by Salt Water Flooding,” advises first responders that “residual salt within the battery or battery components can form conductive ‘bridges’ that can lead to short circuit and self-heating of the battery, resulting in fires.”
In some cases, EVs caught in floodwaters from hurricanes or storm surges have caught fire days later, with the vehicles often burning to the ground. It also bears noting that other Teslas have been spotted suffering similar failures in the wild. It’s possible that some other damage was involved, but it’s not a certainty by any means.
A short-circuited battery gets hot very quickly. This is because instead of the electrical power being turned into mechanical power via the car’s motors, instead, it’s being dumped directly back into the battery and turned into heat. Once hot, lithium-ion batteries often tend to go into a state called thermal runaway. It’s so-called because when in an overheated condition, further reactions occur that generate yet more heat, causing the cell’s temperature to runaway with fire the typical end result.
@chief_miller
Exact reactions involved in thermal runaway are dependent on a given battery’s exact chemistry, but as a guide, most tend to go down a similar path. Per the book “Lithium Ion Batteries: Advances and Applications,” once temperatures inside a cell push past 175 F or so, the anode material begins to break down in a reaction that is exothermic—which means it releases yet more heat. As temperatures push up to 210 F, the electrolyte itself begins to break down, usually releasing gases like hydrogen, carbon dioxide, carbon monoxide, and methane as it does so. This is often visible as lithium batteries fail, with jets of gas bursting out from within the pack. Around 250 F, the separator materials tend to melt, causing a direct internal short circuit between the anode and cathode, releasing energy even faster. Cathode failure then typically occurs around 260 – 300 F in a chemical reaction that releases oxygen as one of its byproducts.
At this point, the batteries are incredibly hot, spewing out flammable gases and oxygen, while surrounding surviving cells are full of flammable electrolyte. Fire is the usual result. As a bonus, the heat from one failed cell in thermal runaway is usually enough to push neighboring cells to the same point in an ongoing chain reaction. Modern EV batteries are designed to limit this spread as much as possible, but engineering can only do so much.
In the case of this Model X, the thermal runaway reaction apparently continued while the car was submerged because the water couldn’t wick away enough heat versus the amount being generated by the short-circuiting cells. The degrading cell products continued to generate more and more heat, releasing flammable byproducts that then combusted with air at the surface. While some oxygen was likely released from the batteries themselves, we can see most of the combustion occurred at the surface where it is most abundant.
It is possible to stop a thermal runaway reaction, but it’s incredibly difficult in practice. The entire battery pack needs to be cooled enough to below the point where the cells are degrading and releasing further energy. This has to go on until the battery is finished dumping energy through any short circuits that might have occurred internally or externally. In reality, it’s difficult to flow water into the overheating parts of a battery to actually achieve this, and thus many EV fires burn on for extended periods of time, or reignite after being put out.
Ultimately, if an EV battery was perfectly sealed and resistant to corrosion, fires like this wouldn’t happen in salt water. Unfortunately, seals are rarely perfect. An EV battery may have great seals that keep out rain and snow on the road and even splashes from deep puddles. Those same seals won’t necessarily work so well when the battery is fully immersed in water, particularly for minutes or longer at a time. Often, breathers are required on battery packs which further complicate the issue of sealing against full immersion.
Fundamentally, you’d want to do your research before trusting your own EV to survive a full dip in salt water. A great example is Rivian, which has notably demonstrated its vehicles fording up to 3 feet of water. We’d trust an R1T for launching a jetski more than we’d trust a Tesla right now, whatever Elon Musk might have said online. In any case, be careful out there!
This isn’t a real story until I read, “Florida Man sets car on fire under water.”
Extremely disappointed that no one thought to barbecue an alligator on it while blasted on five kinds of hallucinogens and some unidentified pills “borrowed” from a horse trailer. Florida…you’re slackin’.
Loose seals can be dangerous! I don’t think this one will be alright, though.
Before this, I was more concerned with loose seals while in the water myself, now we have a whole new problem to worry about.
“Underwater dumpster fire” sounds like the current prospectus for Twatter.
What’s the bill gonna be for environmental cleanup and monitoring? Is that covered by insurance?
EV has fewer fluids than ICE so… less cleanup?
The same amount as for driving an ICE vehicle: 0$
There is no real mystery here. Current from the batteries is shorted through the surrounding salt H2O. This current splits H2O into hydrogen and oxygen providing free oxygen to support an underwater fire fueled by other materials along with some hydrogen floating to the surface where it will also readily combust in the atmosphere (“Oh the humanity”).
Who knew Zoidberg’s Atlanta shell was an EV?!
“We’ve seen a few videos floating around”
That’s Pulitzer price worthy material right there. Bravo.
And what happens to a community on the coast hit by flood waters during a hurricane that has a large proportion of electric cars? Seems like a place NOT to be…
Generally speaking, hurricane flood waters are a bad place to be for humans or vehicles already.
I guess we humans are pretty bad at understanding what fire actually is. We’re too used to our normal, regular fire. When you think of it, water itself comes from hydrogen combustion.
Don’t pretty much all cars act as boats “for short periods of time?” I mean, it all depends on what “short” means to you, even Kennedy’s Delmont 88 didn’t sink immediately like a lead brick
Apparently not Oldsmobiles
https://i.ebayimg.com/images/g/9nEAAOSwyIhiRxRS/s-l1200.webp
Brings new meaning to smoke on the water, eh?
Dammit, now I’ll be hearing that for the rest of the day…
Sorry, not sorry. :-p
And this is why I like LFP – no cobalt, and NO THERMAL RUNAWAY.
Source?
You sound to me like the “do my own research” kind of guy, so why don’t you go ahead and do that.
Not at all! Sorry if I came off that way. I have a background in chemistry and was honestly curious to learn more. I focused on Organic chem so my electrochemistry/inorganic chem is weak.
My thought process is that a lot of battery redox reactions are exothermic (car battery heats up when you crank for a long time) and I was wondering HOW a LFP batter would be resistant to an exotherm in the event of a short.
I then apologize. Apparently, the LFP heats up at a much slower rate, when shorted.
Hey. Its all good. I did phrase that very poorly.
From what I understand, the iron phosphate cathode is just enough less reactive that it doesn’t cause a self-sustaining reaction around room temperatures. It’ll get warm and off-gas enough to bulge the battery, but no fire. Pre-heating it to a few hundred degrees before shorting or damaging it can push the energy up enough to start a fire, though.
I’ve definitely found some papers in the past that tested it officially, as well as less formal tests on youtube, and the empirical results seem to consistently match the theory.
That captain is 100% “Qualified”
I’ve seen fire under water a lot of times unfortunately. You need the obvious things, fuel, oxygen and spark, but also a fourth, enough energy to overcome the heat transfer to the water. Water can extinguish a fire two ways; by depriving the flame of oxygen, or absorbing the heat energy. This was a school science thing when I was young, putting out a candle flame with copper wire. The wire absorbs the heat so fast, the flame goes out. Some of our semiconductor tools create a syrupy residue that is highly reactive, so we would move parts to a water tank right away, just the act of scraping off the residue would input enough energy to ignite the material and have flames underwater. In this case;
The fire might be more visible above water just because of there being far more oxygen. I’m 100% behind EVs, but these events worry me.
Well, a fire needing oxygen isn’t quite true. Fire needs an oxidizing agent, of course the most common one is atmospheric oxygen. A NASA rocket doesn’t use oxygen to burn, it oxidizes aluminum metal with ammonium perchlorate. Oldschool black powder oxidizes carbon with potassium nitrate.
Batteries by definition contain an oxidizing agent and a reducing agent but the reaction is carefully controlled.
Are you speaking to solid fuel boosters? Don’t main engine rockets burn oxygen as an oxidizer from giant liquid oxygen tanks?
The Saturn V used liquid oxygen. The Space Shuttle Rocket Boosters used aluminum and ammonium perchlorate, no oxygen for those ones.
As I ,mentioned above, look up the formula of ammonium perchlorate
I should have said ‘no elemental oxygen’.
You realize all the examples you gave had oxygen in them?
An “oxidizing agent” by definition requires oxygen. NASA uses liquid H2 and O2, some rockets use H2O2, the solid rockets use ammonium perchlorate is NH4-ClO4, note the “O”. There are some species of halogens, but they can’t produce oxygen, just vigorously oxide other metals.
Redox reactions do not by definition require oxygen. Yes, most oxidants contain an atom of oxygen. An example of a redox reaction that does not include oxygen is the oxidation of titanium by nitrogen to titanium nitride.
Sure, but no fire…
In old Salem they tie weights to witches and throw them in the water. If they survived then they were clearly guilty of witchcraft and would be burned. I don’t know why this is relevant but it just seems like too strong a coincidence.
I suspect that a woman who burned to death while they were trying to drown her would likely have been considered a witch. So this Tesla didn’t die an honorable Christian death, I’m afraid.
Electromagnetism IS witchcraft.
They didn’t do that test in Salem, that was a European custom. The idea was that, if one floated, they were being rejected by the water and were, therefore, a witch! If they sank, they were safe, but likely drowned. Salem’s prosecutors preferred the perfect recitation of scripture as a test. They also didn’t burn anyone there, though they crushed a guy during a confession retrieval attempt. Source: grew up in Salem and still go there frequently. There’s more to the city than witches, but you can’t escape the witch stuff even if you try.
“More Weight.”
Giles Corey
16 August 1611 – 19 September 1692
Yup. Apparently, he wasn’t well liked in his day. Don’t know if that had anything to with it or not, but at least he’s remembered in history as going out in a pretty badass way.
My daddy said, “Boy your Tesla’s sinkin’, and it’s goin’ to catch fire is what I’m thinkin’.”
Someone needs to sue Muskrat for all the frickin fish he just killed.
Or something…
And it sounds like DT has been watching People’s Court again with his damn “gasoline burns too crap.” Sounds like weasel lawyer talk here. YMMV
But he’s right. Gasoline vehicle fires happen more frequently. I think he’s being a proper journalist by trying not to frame this in a way that stokes unnecessary fear. EVs catch fire less frequently, but the thermal runaway can be much harder to stop.
It’s important to place this information into proper context. It would be wrong to present EV fires as either easily extinguished or as particularly common. Hybrids have the most frequent fires, then ICE, then EV (all calculated per 100k vehicles).
Agreed. I knew that I should have indicated sarcasm here.
My bad.
Sorry, I should have guessed sarcasm. It’s the Autopian, not Facebook or something. I got roped into being a moderator on Nextdoor, and I think that has broken my internet comment reading skills. It’s awful there.
Just…why? There is nothing I could be offered that would convince me to take that position. 😛
I don’t know why I agreed. I get nothing. I wasn’t really active on the platform, they sent me a thing asking if I would be a local moderator, and I guess I mistakenly thought it would be good for the community. It isn’t. It’s just bad for me. Especially when we had a contentious mayoral election recently.
I guess it keeps me connected to my (fairly awful) local community.
No issues. Sarcasm is just one indicator of a bored mind.
Or perhaps something else at times. Good day sir,
Plus DT is so much fun to harass. Especially since he’s gone all Hollywood. Still waiting to see him on DWTS…
Oh no. Ohhhh no. Thoughts and prayers, friend. Bless your heart. Please remember to scream into the void early and often to preserve your own sanity.
I would 100% believe that ICEs do catch on fire at an elevated rate over EVs. I do have a lot of issues with the “study” that provides those statistics though and believe it should be taken with a grain of salt.
It is simply comparing fires to sales. There have been few EV sales in the distant past. There is no body of shitbox EVs to catch on fire. The website for the “study” even admits this. I would imagine age is a huge factor in vehicle fires. There is also a big gap in sales vs number of total vehicles. EVS make up give or take 5% of the market share, yet 100 times less EVs are registered in the states vs ICE. Sales is NOT an appropriate thing to normalize to unless we are only tracking fires of cars sold within the same period.The hybrid number would be INSANE. In 2022 hybrids made up about 6% of vehicle sales. I think this would come out to 800kish. So almost 30k fires, maybe about .5% of hybrids (assuming 6m are on the road today, couldn’t find a figure for # on road). From what I can tell, this is about 10x the average rate of vehicle fires in the US. (about 170k/year for about 290m vehicles)It doesn’t indicate where any of the data comes from. I have seen it claimed that power source is not factored into any published vehicle fire statistics.EVs are definitely not a bad thing at all, I would consider owning one as a commuter, but I get irked when this study comes up.
Plus I do think the severity of EV fires is actually a very valid concern. Anecdotally I have seen the aftermath of 2 catastrophic vehicle fires. One was a Dodge diesel, one was a Tesla. I imagine a lot more ICE fires can be out out with a water bottle or a fire extinguisher compared to EV fires.
That’s why I won’t quote their numbers; something like 3300/1560/25. But even if you divide that 1560 by 20 or 30 to compensate, you get 78 or 52, still significantly higher than EVs.
I do think there are also some very specific things that give EVs an advantage, such as the lower likelihood of leaking flammable fluids, the reduced powertrain maintenance, and the removal of the exhaust. (Not to mention, the fact that ICE vehicles are using controlled fire to function.) They do have some specific risks, of course: if you pierce the exhaust of an ICE and get saltwater in it, it’s not going to cause a fire.
And I did not mean to imply that the severity isn’t a concern, but that it should be properly weighed against the frequency. Because of some places sensationalizing coverage (Daily Mail comes to mind), you have some people believing that spontaneous EV fires are a common occurrence. It’s good to remind people that fire risks are neither new to EVs nor more common (at least as far as any
On the anecdotal front, I have seen some ICE fires get out of control quickly (I haven’t actually been present for an EV fire), and, while a fire extinguisher can put things out early on, any fire gets beyond that more quickly than a lot of people expect. But, yes, since controlling thermal runaway requires rapid cooling of the battery, it is certainly more difficult to stop, and a fire extinguisher will really only help an EV fire if the fire has not affected the battery. Once it hits the battery, you need a lot of cooling to stop thermal runaway.
I have seen 1 ICE fire in person….it was supposedly some modded BMW at my apartment complex in college (I didn’t get to see the car up close, but it was a spectacle from a medium distance). Totaled the car on either side of it, too. Smoke billowed higher than the 4-story buildings of the complex.
And it apparently just ignited a while after it had already been turned off. Wasn’t like it hit anything. Who knows if mods (again, anecdotally it was modded, I never found a source or anything) had to do with it, but it’s a good mental image for me and a reminder that ICE fires can get pretty bad, too.
Alternatively, yes, I can also take it as “if an ICE fire is this bad, an EV fire is way worse” but as said, we need more data on EV fires. (Brace for rogue statistician jokes…)
Oh wow, I had nice formatting and it all ended up in one giant wall of text.
I’m with you that the conclusions are probably for the most part correct. I hope sometime we can see actual decent data.
Good stuff here. Not really baffeling to me though.
More like free entertainment.
Florida you say? Not surprised a bit…
Boat ramps are an amazing place to just watch stuff. Combine that with Florida Man and a Tesla “that works as a boat”… but actually doesn’t and I’m pretty sure we’ve reached pinnacle entertainment. Grab a beer, a non-conducting folding chair, and enjoy.
This seems to have the stink of insurance fraud somehow.
Florida + Vehicle the owner probably couldn’t afford (or was using as a “biz expense”) + Jet ski
hmmm
Florida Man learns his Tesla loan is underwater. Florida Man has idea.
(chef’s kiss)
Florida Man with a Tesla is still Florida Man.
Florida Tesla Man is an absolutely horrifying proposition
…why couldn’t Musk have moved there instead?
Signed,
Texas
Was it a man backing the Jet Ski on the ramp, it mentions wife was in the car and warning appeared, he saved her. Who was driving?
Florida Man, natch.
Its supposed to be smoke on the water, fire in the sky, not fire in water, smoke in the sky
“…some stupid with a jet ski…burned that X under pond…”
Yeah; wouldn’t be to tough to rewrite that song
Of fucking course it was a Tesla and it was in Florida. The jokes write themselves.
sounds like the Cuyahoga river
This is just Tesla disrupting the outdated water–fire paradigm.