In any claim for compensation, where the employee (i) is physically or mentally unable to testify as confirmed by competent medical evidence, (ii) dies with there being no evidence that he ever regained consciousness after the accident, (iii) dies at the accident location or nearby, or (iv) is found dead where he is reasonably expected to be as an employee, and where the factual circumstances are of sufficient strength from which the only rational inference to be drawn is that the accident arose out of and in the course of employment, it shall be presumed the accident arose out of and in the course of employment, unless such presumption is overcome by a preponderance of competent evidence to the contrary.
Va. Code § 65.2-105