David Chandler has created a video for AE911Truth that, he claims, contains evidence for the sound of explosions at the WTC7. Here is the video, hosted by ae911truth: Skip the first 2 minutes with some other truther claims (Sunder; McPadden; Bartmer...), and jump right ahead to the 2:04 mark where Chandler introduces us to the NBC clip here NBC's Ashleigh Banfield interviews a woman she calls "Fabiana" as WTC7 collapses in the background. They are on the intersection of West Broadway and Worth St, as you can confirm with Google Street View. This is roughly 570 meters (1870 ft) from the nort-east corner of the old WTC7. Back to Chandler: At 2:47, he lets the clip run, filtered to sound only basses. At 3:05 he marks where he thinks he hears a series of explosions: The first sounds as "Fabiana" says "they..they (advised us to leave)". These can't be explosions that caused the collapse of any part of WTC7! Here is why: Look at the NBC clip as NBC has it in their archive: http://www.nbcnews.com/video/nbc-news/14516622?hc_location=ufi#14516622 Watch closely, and listen: From 0:00 to 0.05, you see a narrow strip of bright sky down West Broadway 0:00: Crop of the region I mean: 0:05 thumbnail: Crop: Then, at 0:06, a dust cloud develops and fills that bright area from below: Thumbnail: Crop: From 0:09 I can hear a rumble start to swell As the time changes from 0:10 to 0:11, Fabiana says "they they" - this is the moment that Chandler detected his first "explosion" At 0:12, Banfield turns her head in reaction to the rising noise level. So, at 0:06, there is already a dust cloud. This means that the WTC7 facade at that point in time already must have burst - this must be more than one second after the north perimeter started to descend, which therefore happened at or before 0:05 s in the video. This in turn means that the east mechanical penthouse had already dropped as the NBC clip starts. The distance, no more than 600 meters, means that sounds travels no longer than 2 seconds. An explosion sound that could have caused column 79 to buckle therefore would have been heard at or before 0:02, or it would have been before the clip starts. Any explosives that broke the exterior columns would have to have been heard at or before 0:08 seconds. Those would have been the last explosions - but Chandler heard his first at 0:10/11 - about 2.5 seconds too late! And that debunks his claim that the NBC-clip contains audio evidence of demolition explosions.