MwRYum
Major
Unofficial accounts said that the fire department initially called in were not informed of the nature of the fire - all they knew at that time was there's a warehouse fire in progress (it was warehouse alright, but one that stores dangerous chemicals), first responders arrived on scene only realised something amiss when they first hosed down the flame - just about the time crew chief called everyone back off it went kaboom.It may be of some comfort that the affected area appears mostly to be Warehouses and Vehicle storage rather than dense residential. The housing blocks affected seem low rise blocks and old styled.
Not trying to belittle the impact, but at least the casualties will be only a fraction of what they otherwise could be.
On another note, the Tianhe-1 supercomputer cluster is housed within that very industrial district, while official statement claimed the shut down was merely precautionary and the physical clusters are undamaged - can't say the same about the building.

The building is about 2km away from ground zero but look at those shattered windows, this is no small boom.