It's the description of a wave with force that makes this a curiosity and one wonder why it hasn't been officially "reported"...
maybe they need to wait 30 years
Explosions can be categorized into two general categories, as follows.
In a deflagration, the combustion or reaction wave propagates at a velocity less than the speed of sound. Although all combustion (fires) can be defined as a deflagration, the ignition of a fuel-oxidizer mixture or a suspended cloud of combustible dust in a confined environment typically causes a significant and rapid increase in pressure that can cause catastrophic damage. These explosions are typically associated with natural gas or propane releases (gas explosion), gasoline and hydrocarbon vapors (vapor explosion), finely divided fuels (dust explosion), and certain reactive chemicals . These events can occur immediately before, or immediately after a fire and can propagate throughout a facility. Therefore, an engineering investigation of the event typically includes the preceding and subsequent events.
In a detonation, the combustion or reaction wave propagates at a velocity faster than the speed of sound. Due to the very fast reaction, these explosions create a high-pressure shock wave that causes significant damage at large distances from the seat of the blast. Detonations which can create significant brissance, or fragmentation, of containment vessels, causing impact and penetration damage are typically fueled by solid or liquid fuels but can also occur in pressurized or oxygen-rich-gas environments. They usually are associated with blasting agents or munitions (high explosives). Certain chemicals can also be boosted into detonation with a proximate high-explosive charge. A fire within a chemical warehouse or storage area may also cause a deflagration-to-detonation transition (DDT).http://www.exponent.com/explosions/