Not ordinary fires
I do not want to say much about the Australian fires - but this photo of molten metal from burnt cars gives you some idea of their intensity.
For the record - apparently these were aluminium alloy wheels. The melting point is just under 1000 kelvin. Way hotter than lead (600 kelvin). Iron melting point is 1800 kelvin - furnace temperature. There are incidents of iron being serious impaired (eg children swing sets that collapsed with heat damage) but I have not seen plausible photos of iron melting like this...
J