It was thought to likely be an electrical fire in the offices at one end of the building, but it had lots of flammable things inside it, but also no real fire breaks/containment like you'd have in a modern building. Wooden floors, wooden furniture, lacquered surfaces, lots of potted trees, cluttered exhibits and low budget concessions. The fire became unmanageable really quickly and presumably once glass is falling from a great height, it becomes unsafe to tackle any individual aspect.

But it was also really a neglected building by then; it was not the glamorous event space it was designed for when it was on the Hyde Park site. The money was running out for the company running it at Sydenham.