[bmelton]

Meteor Chelyabinsk suffered catastrophic fragmentation, a rapid, violent release of energy accompanied by a pressure wave with debris, which would satisfy the definition of an explosion (an in fact the energy released was equivalent to 400-500 kilotons of TNT.)

[jojobas]

If you could look at this catastrophic fragmentation you'd find it's about the same pace as dirt spreading on the ground as it gets tipped off a dump truck. The fragments outward speed is negligible compared with their forwards speed, and it's the forward speed that produces the shockwave, fragmented or not.