This is the location where the blast occured. The fire seems to cover most of the area between Buncefield Lane (west), Cherry Tree Lane (north), Green Lane (east) and the little by-road to the south. It seems that most of the northern half of the terminal has been destroyed by the blast.

What exactly happened, will probably never be found out. Some suggestions are that petrol leaked from a pipeline, turned in to vapour and was ignited by a spark.