# Fires in New Orleans **URL:** \ **Category:** Factual Questions\ **Created:** [September 4, 2005, 5:15pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061 "2005-09-04T17:15:32Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Gymnopithys](https://avatars.discourse-cdn.com/v4/letter/g/fbc32d/32.png) [@Gymnopithys](https://boards.straightdope.com/u/Gymnopithys)\ **Post date:** [September 4, 2005, 5:15pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/1 "2005-09-04T17:15:32Z")
What started the fires in New Orleans 3 days after the storm. Any known causes ? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [September 4, 2005, 7:56pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/2 "2005-09-04T19:56:21Z")
To the best of my knowledge, the causes are not known at this time, but some _possible_ causes include: - nutjobs setting fires - accidental spread from fires intended for cooking, heating (not likely this time of year, though), or light - natural gas pipe leaks igniting - electrical shorts - volatile chemicals mixing and self-combusting Fires can smolder several days before erupting into visible flames. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [September 5, 2005, 1:42am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/3 "2005-09-05T01:42:46Z")
Not to hijack, but did you see that live shot on TV of flame burning above the waterline in the middle of a street from (seemingly) nothing? What the heck was that??? - Jinx ---
**Author:** ![percypercy](https://avatars.discourse-cdn.com/v4/letter/p/8baadc/32.png) [@percypercy](https://boards.straightdope.com/u/percypercy)\ **Post date:** [September 5, 2005, 1:46am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/4 "2005-09-05T01:46:29Z")
Obviously Arson investigation is pretty low on the priority list, but both Canal Place and the shoe store at the corner of Canal and Carondolet had recently been looted. IMO there’s a group looting and burning. I’m not sure any cause has been determined for the warehouse fire. -Lil ---
**Author:** ![Tenar](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@Tenar](https://boards.straightdope.com/u/Tenar)\ **Post date:** [September 5, 2005, 1:50am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/5 "2005-09-05T01:50:45Z")
> [@Jinx](#): > > Not to hijack, but did you see that live shot on TV of flame burning above the waterline in the middle of a street from (seemingly) nothing? > What the heck was that??? - Jinx Sounds like a gas leak, maybe? ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [September 5, 2005, 2:12am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/6 "2005-09-05T02:12:00Z")
> [@Tenar](#): > > Sounds like a gas leak, maybe? Yes, but where’s the source of ignition (especially in relation to the water level)? The water was pretty deep! I can’t quite picture imagine how this can happen. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [September 5, 2005, 3:48am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/7 "2005-09-05T03:48:43Z")
When natural gas and air mix in the proper proportion they will spontaneously ignite. No spark required. It doesn’t always happen, but given the number of leaks in the area random chance would cause a couple of these instances. I forget the exact mix required, but it’s something that can happen with natural processes. ---
**Author:** ![Rikster](https://avatars.discourse-cdn.com/v4/letter/r/e9a140/32.png) [@Rikster](https://boards.straightdope.com/u/Rikster)\ **Post date:** [September 5, 2005, 4:50am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/8 "2005-09-05T04:50:23Z")
I know its hot in New Orleans but the best cite I could find for natural gas spontaneously igniting is 1200F. It may look and smell like hell down there right now, but I doubt it is that hot. Could you provided a better cite? [http://members.fortunecity.com/brucedp/attsv/quick\_ref\_fuel\_guide.htm](http://members.fortunecity.com/brucedp/attsv/quick_ref_fuel_guide.htm) ---
**Author:** ![Gymnopithys](https://avatars.discourse-cdn.com/v4/letter/g/fbc32d/32.png) [@Gymnopithys](https://boards.straightdope.com/u/Gymnopithys)\ **Post date:** [September 5, 2005, 6:48am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/9 "2005-09-05T06:48:19Z")
Electrical shorts should be ruled out since there was no electricity. ---
**Author:** ![Beware\_of\_Doug](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Beware\_of\_Doug](https://boards.straightdope.com/u/Beware_of_Doug)\ **Post date:** [September 5, 2005, 8:09am UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/10 "2005-09-05T08:09:11Z")
Besides, I don’t think very many people would wear them outside the… :smack: Oh, never mind. One interesting explanation I’ve heard is that fire insurance pays off a lot better than flood insurance. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [September 5, 2005, 12:44pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/11 "2005-09-05T12:44:13Z")
> [@Rikster](#): > > I know its hot in New Orleans but the best cite I could find for natural gas spontaneously igniting is 1200F. It’s not the _temperature_ that does it, it’s the _mixture_ of gas and oxygen that leads to a spontaneous chemical reaction releasing sufficent heat to cause combustion. I don’t have a cite - just memories of a demonstration in high school chemistry. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [September 5, 2005, 1:52pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/12 "2005-09-05T13:52:19Z")
I’m sure that the reasons vary. I’ve heard of a high-rise housing project that burned; that was probably a fire that was started to cook food and/or boil water. Most of the stores were probably burned by looters. That warehouse was probably a chemical explosion. Probably, a couple of chemicals got mixed that you really, really want to keep seperate. Also, there are chemicals that react violently with water, and need to be kept dry for this reason. ---
**Author:** ![Mycroft\_Holmes](https://avatars.discourse-cdn.com/v4/letter/m/a5b964/32.png) [@Mycroft\_Holmes](https://boards.straightdope.com/u/Mycroft_Holmes)\ **Post date:** [September 5, 2005, 2:12pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/13 "2005-09-05T14:12:22Z")
> [@Broomstick](#): > > It’s not the _temperature_ that does it, it’s the _mixture_ of gas and oxygen that leads to a spontaneous chemical reaction releasing sufficent heat to cause combustion. > > I don’t have a cite - just memories of a demonstration in high school chemistry. I’m a Chemical Engineer and I have never heard of a mixture of natural gas and air self-igniting. Here is a link to a [Material Safety Data Sheet](http://www.uniongas.com/aboutus/safety/MSDS2003.pdf) for natural gas. It says: > [@](#): > > Natural gas can present an extreme fire hazard when mixed in appropriate > concentrations with air **in the presence of a viable ignition source. (bolding mine)** and > [@](#): > > Ignition Temperature (°C) > Approximately 593° The only thing that might cause self-ignition is Chlorine dioxide (maybe that’s what was demonstrated in the experiment you remember?). Chlorine dioxide is mostly used to bleach paper pulp, so I don’t think it is something that would just be lying around. ---
**Author:** ![Harriet\_the\_Spry](https://avatars.discourse-cdn.com/v4/letter/h/e56c9b/32.png) [@Harriet\_the\_Spry](https://boards.straightdope.com/u/Harriet_the_Spry)\ **Post date:** [September 5, 2005, 7:45pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/14 "2005-09-05T19:45:54Z")
Carelessly discarded matches or cigarettes could be a source of ignition. Also, if people are running things off of generators, couldn’t there be electrical shorts from that? ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [September 5, 2005, 7:56pm UTC](https://boards.straightdope.com/t/fires-in-new-orleans/320061/15 "2005-09-05T19:56:51Z")
> [@Mycroft Holmes](#): > > The only thing that might cause self-ignition is Chlorine dioxide (maybe that’s what was demonstrated in the experiment you remember?). Chlorine dioxide is mostly used to bleach paper pulp, so I don’t think it is something that would just be lying around. Even in pulp mills you wouldn’t have ClO2 lying around. Because of the inherent hazard in the chemical and its tendency to spontaneously decompose chlorine dioxide is generated on site as a low concentration solution in water with only a limited amount of storage.