Well done to them, as this could have been such a different story!
As yet there is no idea of the cause, but this summer the ground is very very dry and the least little spark could easily turn into an awful disaster. People are warned to take care when having picnics or walking in the counrtyside etc to take all their rubbish away with them and also be careful when smoking....do not throw cigarette ends to the floor discard of them in a responsible way, and certainly don't throw them out of the car window!
The photos here show just how close the fire was from peoples homes!