The debris fell in because the explosive wasn't very big (used loosely) -- it went off, caused damage, the brick facade fell into the street. Old brick structures aren't really that sound, it doesn't take much to demolish them. I don't think this was an explosion as much as it was a deflagration. The difference between a detonation and deflagration is the speed at which it occurs. Explosions are faster than the speed of sound, deflagrations are more of a burn / expanding gas. The ATT building was hardened, as in, meant to withstand a hurricane taking no damage. The expanding pressure wave likely entered into the building as it had some openings, with the building pressurized and connected to the road, that overpressure likely lifted those panels in front of it. The over-pressure entered the building, was gone outside, continued through the building under ground blowing up those covering plates. 1000lbs of detonation would have cratered the street (may have, not like we have a good picture of everything), 1000lbs of deflagration would have been big fireball and still overpressure, just not like explosion. I've only seen a few photos -- however I was able to accurately estimate the blast of the port in lebanon using sat photos and drone shot of the crater.
ANFO is a go-to most IEDs, but this had a lot of fire so I'm curious if the guy didn't just go hollywood and use lots of liquid fuel (causes fireballs). In one of the videos something appears to shoot off and appears to have a trail behind it, possibly a compressed gas cannister. This could have been a hodgepodge of stuff, possibly smokeless powder, gas, acetylene, could have used the RV's volume to further boost it using acetylene / oxygen + physical components. It looks dirty either way meaning it wasn't a homogenous explosive mix.
Why is the debris field protruding into the street instead of out of?
The debris fell in because the explosive wasn't very big (used loosely) -- it went off, caused damage, the brick facade fell into the street. Old brick structures aren't really that sound, it doesn't take much to demolish them. I don't think this was an explosion as much as it was a deflagration. The difference between a detonation and deflagration is the speed at which it occurs. Explosions are faster than the speed of sound, deflagrations are more of a burn / expanding gas. The ATT building was hardened, as in, meant to withstand a hurricane taking no damage. The expanding pressure wave likely entered into the building as it had some openings, with the building pressurized and connected to the road, that overpressure likely lifted those panels in front of it. The over-pressure entered the building, was gone outside, continued through the building under ground blowing up those covering plates. 1000lbs of detonation would have cratered the street (may have, not like we have a good picture of everything), 1000lbs of deflagration would have been big fireball and still overpressure, just not like explosion. I've only seen a few photos -- however I was able to accurately estimate the blast of the port in lebanon using sat photos and drone shot of the crater.
ANFO is a go-to most IEDs, but this had a lot of fire so I'm curious if the guy didn't just go hollywood and use lots of liquid fuel (causes fireballs). In one of the videos something appears to shoot off and appears to have a trail behind it, possibly a compressed gas cannister. This could have been a hodgepodge of stuff, possibly smokeless powder, gas, acetylene, could have used the RV's volume to further boost it using acetylene / oxygen + physical components. It looks dirty either way meaning it wasn't a homogenous explosive mix.