Audio wave record
The audio wave evidence supports the seismic evidence.
VIDEO: “9/11 Eyewitness video – sound analysis shows explosives prior to the collapse” by Rick Siegel. DVD from 911eyewitness.com. Dailymotion
In this video of the North Tower collapse made by Rick Siegel of 9/11 Eyewitness, the audio wave is juxtaposed against the sound recording. Audio wave spikes start to appear 17 seconds before the start of the fall of the tower (-17 seconds) and each spike is accompanied by a roaring boom sound (Ondrovic also heard a roaring sound when she the towers started to collapse – the characteristic roaring sound of a nuclear explosion). There are four spikes before the building starts to collapse:
1) -17 seconds = medium to large spike
2) -13.4 seconds = small spike
3) -7.4 seconds = medium spike
4) -3.5 seconds = medium spike
5) 0 second = start of cascade
6) +2 seconds = very large spike (first nuclear detonation)
7) +10 seconds = very large spike (second nuclear detonation)
8 ) +14 seconds = very large spike (Mach effect  of reflected wave, no accompanying boom sound)
VIDEO: MACHSTEM Dailymotion
After four of these small and medium-sized spikes, the collapse begins (at 0 seconds). Two seconds into the collapse, there is a huge spike. This appears simultaneously with the formation of mushroom clouds and pyroclastic flows that shoot up and out and then cascade down, with much ejection of material (at 45 degree angles).
A second giant spike appears at the 10 second mark and this coincides with a brightening of the screen and further acceleration of the energy of the collapse. The steel spire in the foreground of this video: Tower1_dust_cloud_afterglow  turns into a spray of dust at this point.
VIDEO: Tower1_dust_cloud_afterglow Dailymotion
Another 9/11 Eyewitness video of the audio wave for the North Tower :
VIDEO: 911 Eyewitness video of the audio wave for the North Tower Dailymotion
In this GIF image , you can see a smoke plume at the base of the Twin Towers. It was broadcast only on CNN. After it was broadcast once it was never shown again .
GIF  of explosion plume arising to one side of the base of the Twin Towers.
The South Tower has not exploded yet. There is some confusion about when the plume occurred. CNN told AFP investigative reporter Bollyn that the plume occurred immediately after the South Tower was hit by a plane . The South Tower was struck at 9.02 am . However other visual depictions show the plume cloud appearing just before or at the same time the South Tower collapses (at 9.55 am)
The German Engineer’s site has photos that show the plume clearly. The caption “New explosion in World Trade Center” probably refers to the explosion(s) seen with the collapse of the South Tower. As can be seen in the screen shot of the CNN broadcast, the smoke plume is of great size and spreading out covering most of the buildings in that area. That is what we saw in other videos and photos of the WTC 2 collapse. No such smoke plume filled the space between the towers and other buildings when FL 175 struck WTC 2, so the plume shown in the CNN video that appears to the left of the screen occurred at the time of the WTC 2 collapse, not when it was hit by a plane. Besides only one tower appears in the screen shot on the right with the smoke plumes. In the middle photo, there are two distinct smoke plumes, one that is whiter and more dense and is located lower, and another that is longer, gray in color and is located posteriorly to the lower one.
German Engineers Help the USA: WTC 6 explodes 
The researcher in this video below  investigates the plume in more detail.
VIDEO: 911 Ground Zero Part 2 Dailymotion
In this 9/11 Eyewitness video , a plume arises at the foot of the North Tower simultaneously as the North Tower begins to collapse. The perpetrators synchronized the detonation of preplanted explosives in WTC towers 3, 4, 5, and 6 with the detonation of the bombs in the Twin Towers to make it appear as if their destruction was the sole result of collateral damage from the collapses of the Twin Towers.
VIDEO: 911 Eyewitness – Witnesses reported rumbling and dust clouds before collapse Dailymotion 
[Pic from Arsenal of Hypocrisy]
Aerial view of Ground Zero. WTC 6 is in the top right corner. Photo .
Map of the WTC . Note the position of WTC 6 relative to WTC 1 and 2 and the Hudson River.
Every building with a WTC prefix was completely destroyed or extensively damaged . In this aerial shot you can see the cratered WTC 6 building in the top right hand corner of Ground Zero.
WTC 6 was extensively damaged in the WTC disaster. Aerial photography shows a huge crater in the center of the building with smaller holes surrounding this cratered section.
Aerial view of the partially destroyed WTC 6. To the left of it are the remains of WTC 1. 
If this building had been destroyed by a thermonuclear device, the device had a very low yield, lower than the yield of the thermonuclear bombs used in the Twin Towers. The perpetrators favored the use of nuclear devices to destroy the buildings because of their compact nature and the characteristics of their explosive effects. These detonation of just one or two of these devices produce a total effect that more closely mimics a tidal wave of destruction emanating from the one cause (universal weakening of the building supports). Conventional ordnance could have been used instead of nuclear devices but their use poses great logistical problems. Conventional ordnance was used in a supporting role.
The timing of the destruction of WTC 6 was intended to coincide with the destruction of South Tower to make it appear as if the collapse of the South Tower caused the damage to WTC 6. The perps had to place ordnance in the WTC 6 themselves as there was no guarantee that WTC 6 would be significantly damaged in the WTC 2 collapse. This is why an ordnance plume appears at the foot of the Twin Towers even before the South Tower begins to collapse and why the seismic record shows spikes before the collapse starts.
The other 3 early spikes and booms that occur before WTC 2 starts to collapse are evidence that multiple explosions occurred before its collapse. These could have been further detonations of WTC 6 or detonations of the other towers in the complex (WTC 3, 4, and 5). WTC 7 collapsed about 5 hours after the Twin Towers, and was intact until then. These buildings were extensively damaged in the WTC disaster .
In this aerial shot, the ruins of WTC 4 (bottom left), WTC 5 (bottom right), and WTC 6 (top right) can be seen . Only the north wing of WTC 4 remains.
The map shows the location of the seven WTC towers. From this map it can be seen that most of WTC 4 was destroyed except for its north wing. 
WTC 1, 2 and 7 completely collapsed in this disaster. WTC 3 (the Marriott Hotel) was destroyed except for three floors. WTC 4 was all destroyed except for one wing (North wing), WTC 5 was extensively damaged, and the middle of WTC 6 was gouged out.
WTC 3 (Marriott Hotel) 
The aim of the perpetrators was to destroy all 7 towers and to make it appear as if the plane crashes had set of a sequence of events that resulted in their destruction. WTC 3, 4, 5, 6 were clandestinely destroyed by pre-planted ordnance devices which were set to detonate at the same time the Twin Towers collapsed. It appears the timing was slightly off as videos capture a smoke plume rising to the left of the Twin Towers before the demolition cascade of the South Tower even begins, and the sound recordings and seismic records confirm the occurrence of four explosions before the South Tower starts to collapse.
There is also visual evidence that these towers were exploded. In the aerial shots of WTC 6, there is a pattern of ‘holes’ that suggest explosions took place. Most explosives cause a spherical pattern of destruction around the center of explosion, and these spheres of destruction appear as circles and craters in aerial views. In the aerial views of the WTC 6 shown below, the circles that appear are well-defined.
WTC 6 ‘holes’ . Photo 
Similarly, the round punched-out areas in this aerial photo of WTC 5 are consistent with the detonation of explosives. It is extremely unlikely that falling debris punched out circular holes in the buildings.
WTC 5 ‘holes’. Photo 
The remains of WTC 6 (top left) and WTC 5 (bottom right of the picture). 
Aerial view of the damage to WTC 6. 
Eyewitness accounts of “basement” explosions
Because of the proximity of the Twin Towers to WTC 6 and the fact that they shared the same foundations (Bathtub and basement level floors) meant that the firefighters and other personnel in the South Tower who were in the basement or lower levels of the South Tower experienced the effects of that explosion (and the explosions of the other towers – WTC 3, 4, and 5).
There are many first-hand eyewitness accounts of ‘basement’ explosions occurring before the towers started to collapse.
lack of damage to the basement and bathtub, perps didn’t want flooding because people will wonder why the bathtub cracked, but later it did crack and millions of gallons of water from Hudson River flooded basement – kept quiet.
- angled cut to beams
- WTC7 – chapter by itself
- warnings given – helicopeter, WTC7, Patricia Ondrovic
- passed WTC6 – popping lights – timed explosions
- miracle survivors
- outline process of demolition
- series of explosions – match up with seismic data
- steel core, placement of nukes?
- placement of the other charges
- arch of destruction
VIDEO: Rick Siegel 9-11 Eyewitness Documentary