The blast wave, depending on the size of the blast, can travel much faster then the speed of sound. And this was one big blast. I’d said about the size of a tactical nuke, 1 or 2 kilotons, so I think it is a safe bet that the blast wave exceeded the speed of sound.
Well, no. Technically, the speed of sound (in any given material) IS the maximum (and minimum also) speed of a blast wave in that substance.
Now, a bigger (faster or “sharper”) blast will create a larger pressure differential across that blast wave, but the speed of its arrival is the same in the same air conditions everywhere. A slowly expanding blast - like from a fire or burning of gasoline - will more slowly “ramp up” the pressure wave than a rapid explosion. But both travel at the same speed through air.
The shock wave going through rock is faster than that through dirt, faster in dirt than water, and all dense materials are much faster than air. So you would have seen the light waves - arriving at the speed of light - then felt the ground move, then feel the air blast.
It CAN?
I guess I must have been sleeping in my high school physics class the day the teacher taught the mysterious forces that can cause that effect.
(It IS true, however, that sound WILL travel faster through a solid or liquid medium than it will thru air.)