There was an incredible amount of smoke just half an hour ago. We saw the column of smoke from our offices in the City even though we're hemmed in by tall buildings. If it had only been a few streets away I would have thought it a large fire. By the time I went outside the column had collapsed and you could tell the true distance. If it is an old bus garage then I suspect there are a few old tyres and drums of diesel to add to the smoke, not to mention that the concrete would have been soaked in diesel anyway.