It was not vacant for the renovations, it was vacant because it was Saturday night. Rest of thw week it was fully inhabited, everyone working as usual.
That's the worrying thing, had it been 1PM on monday, and hundreds could have DIED. The fire extinction systems didn't work!
And I agree with Fernando, this doesn't give me good feelings about M2012, it's been a sad week just after the Olympic comitee departed, a bombing and a huge fire... we don't feel very confident.