Two fires that destroyed 19 homes in Stourbridge were started accidentally in fields where farming machinery was in use, according to West Midlands Fire Service.
Investigators established farming equipment was being used in the vicinity of fields immediately before the fires were first reported.
The first fire started in a field near Racecourse Lane at about 13:27 BST on 13 August, while a second began shortly afterwards in a field near Quarry Park Road.
Chief Fire Officer Simon Tuhill said so many people had been affected the service he wanted to confirm both fires were not started deliberately. They were accidental, he said.
“While investigations continue into the full circumstances of what happened, we wanted to share this latest update as soon as possible,”Tuhill continued.
“I hope it will go some way towards helping people understand what happened on that exceptionally hot and challenging day.”
As well as the properties that were completely destroyed, a further 18 were damaged as the flames spread rapidly through grass and woodland.
The incident in Stourbridge happened on the UK’s hottest day of the year as temperatures peaked at 38.1C in some parts of the country, the Met Office said.
Several other fires were reported in the West Midlands on the same day as a total of 54 patients were treated by paramedics and 19 were taken to hospital.
Other incidents saw about a dozen homes lost in Birmingham, four in Stoke-on-Trent, three in Pershore, Worcestershire and three in Willenhall, near Wolverhampton.
The causes of most are still under investigation, although it was confirmed a barbecue started the one in Stoke on Trent.
