Another day, another devastating fire at a derelict mill in Yorkshire.
In the latest incident, a disused paper mill on Great Horton Road in Bradford caught fire on Monday night.
These relics of Yorkshire's manufacturing heyday have always been prone to combustion - during their operational life, when Victorian fire prevention regulations were woefully inadequate, it was common for blazes to break out, as the buildings were full of flammable cloth and lit by naked flames.
Yet a Historic England investigation in 2017 found that there had been over 100 fires at derelict mills in Bradford alone since 2010.
Drummonds Mill and Prospect Mills were both severely damaged, while Newsome Mill in Huddersfield and Bank Bottom Mill in Marsden were also struck by major fires. A teenager was convicted of arson after setting fire to a four-storey mill on Rebecca Street in Bradford that had recently been brought back into use as business premises in 2017.
These are some of the reasons why mill fires are so common...
The fact that they're empty
Yorkshire is full of derelict mills, and many of them can be easily accessed by trespassers. It's simply far easier to set fire to an empty building than a secure, well-maintained, occupied one. Some have started as a result of rough sleepers lighting fires to keep warm, while others have been ignited by vandals or have been deliberate acts of arson. Without security or sprinkler systems, it's easy for fires to take hold.
A large number of Yorkshire's mill fires have started in suspicious circumstances, although in some cases it has been impossible for fire investigators to convict anyone of arson due to a lack of evidence once the buildings have been destroyed. In the 2016 fire at Prospect Mills in Thornton - the third in five years at the site - youths were seen running out of the building, which had a long-standing problem with rough sleepers sheltering there. As all utilities had been disconnected, deliberate ignition was the most likely cause.
Teenager Hamza Nadeem, who was said to be obsessed with fires, was convicted of starting the blaze which caused £500,000 worth of damage at a newly-refurbished mill on Rebecca Street in Bradford. The 18-year-old was given a four-year prison sentence.
Flammable dust and materials
Many old mills haven't been properly cleared, so flammable material is still present - particularly dust. A huge fire in 2016 at Drummonds Mill in Bradford - a Grade II-listed icon of the city's history - started in the basement, where cardboard boxes had been stored. The mill was being used as accommodation for community arts groups and the owners had hoped to eventually convert it into flats. It had to be demolished following the fire.
Although mill design did develop and evolve over time to prevent fires, it had always been difficult to fire-proof them. Early lessons were learned during the buildings' operational lives, when fires would break out when accumulated grease, oil and discarded fibres left on the mill floors would ignite. Wooden floors were later replaced by materials such as cast-iron columns, steel frames and concrete. But in extreme heat, even cast iron, steel and brick arches will collapse.