I just read that in a book called Aftermath, Inc.: Cleaning Up After CSI Goes Home. I know that “the pile”, as they called it, of the remains of the WTC were massive, but really? Five months to be completely extinguished? No offense intended by this question, I just find it rather mind-boggling.
I don’t find it hard to believe in the least. I went by the ruins around Thanksgiving 2001 and there was still a lot of smoke rising from the ruins.
Low level combustion can continue for a long time. Some underground coal seam fireshave continued for decades.
Well, to be fair, the stuff that was burning was under a massive rubble pile. Rather hard to reach it to extinguish it. Also, don’t think in terms of engulfed in flames, but rather smoldering.
You can stir up a camp fire 2 or 3 days later and find smoldering embers. It doesn’t surprise me at all that a huge, cavernous pit covered with rubble could continue smoldering for months and months.
Remember too the lessons of spontaneous combustion, as seen in fermenting haystacks.
You have a very large pile with very poor heat conduction characteristics. it has burning material buried inside. (The pile for each tower was several stories tall, and extended a hundred feet underground. There may not be active flames, but some of that buried rubble was extremely hot burning material. The heat has nowhere to go, it stays there. If you uncover it, like Leaffan points out about stirring embers, suddenly this material gets plenty of oxygen and may burst into flame… or at least, smoulder faster. Pouring massive amounts of water onto it does not guarantee that water penetrates everywhere, but does make cleanup that much harder and messier. I assume they just sprayed the parts they had to work with.
(When I saw it 3 weeks after, even the WTC7 pile was 30 to 50 feet high, and that was the small building - no surprise the cleanup took 5 months to reach close to the bottom.)
Doesn’t sound surprising to me. Here in Chicago there was a warehouse fire near I55 and California Ave. in 1998 (IIRC) and you could see it smoldering from the highway for months.
And, of course, there are the tire-pile fires that burned for years. One actually produced a hydrocarbon runoff that was worth collecting and sending to a refinery.
I forgot to mention, too, that there was a subway line under the WTC, and the PATH train tunnel to Jersey. So simply “fill the hole with water” was never a useful option. You would just have to pump it out the bottom with no guarantee you were soaking everything.
I was there at Christmas 2001, and there was definitely something still burning.