The War of the World was written by H. G. Wells over a century ago. It is still as popular today as it was back then. It’s a timeless classic. It was written when science fiction was just beginning its journey as a genre.
Eventually the humans realize that something has gone wrong with the aliens, they have somewhat slowed down with their activities. Their fear of the aliens has calmed down a bit, they try to take a look at what is happening. In one of the alien machines, a dying alien is discovered. The aliens are dead or dying because they have been infected by bacteria, to which all humans are immune. The aliens have not evolved an immunity to this bacteria! Earth is saved by God’s wisdom.