In Jeff Wayne's War of the Worlds, what happens to Parson Nathaniel to render him unconscious?

In The Spirit of Man, Parson Nathaniel has the line:

Nathaniel : Those machines are just demons in another form. I shall
destroy them with my prayers, I shall burn them with my holy cross. I
shall...

And then clunk, he just falls over unconscious. Is it explained anywhere what actually caused this to happen?