Does the prosecution need to "rule out all possible or imaginary causes of the fire"?

The prosecution need not "rule out all possible or imaginary causes of the fire[]." (People v. Andrews, supra, 234 Cal.App.2d at p. 74.) There is "no requirement that the whole gamut of speculative possibility as to the cause of the fire[] be run, and then each, in turn, be ruled out." (Id. at p. 76.) "Were the rule otherwise it would, as a practical matter, in the absence of a plea of guilty, be necessary to strike arson from the list of prosecutable crimes. Incendiarism is rarely carried on in the presence of eyewitnesses." (People v. Andrews (1963) 222 Cal.App.2d 242, 244.)