One cant rule of some sort of explosion because of broken columns. However, when the nakumatt on kimathi street stores caught fire and building collapsed, was KDF there? It was started by mattresses in the nakumatt store where KDF soldiers cornered the al-kebaabs, and they began lighting mattresses one by one and dropping them down to the KDF, some improvised "tear gas", but the store caught serious fire, which messed up the integrity of the structure, perhaps followed by some explosions of turpentine cans, gas cylinders in restaurant kitchens nearby, e.t.c and other explosive material in the stores, at least that's the KDF version which i tend to believe.
Ras Kienyeji Man