flecc pointed out some time ago that the fire could have propagated through cooker hood fume extraction ducts.
In fact, most catastrophic fires are not due to just one cause but a concurrence of more than one mistake.
Years ago, one of my clients had a printing firm. A faulty PSU on a PC sitting under a desk set fire to the desk, the desk set fire to the window frame etc.. you can guess the rest. The chance that a faulty computer PSU setting fire to a desk is very small. Nobody could imagine that window frames could catch fire etc. so the building did not have sprinklers.
In fact, most catastrophic fires are not due to just one cause but a concurrence of more than one mistake.
Years ago, one of my clients had a printing firm. A faulty PSU on a PC sitting under a desk set fire to the desk, the desk set fire to the window frame etc.. you can guess the rest. The chance that a faulty computer PSU setting fire to a desk is very small. Nobody could imagine that window frames could catch fire etc. so the building did not have sprinklers.