Va. Code Ann. § 27-34

Whenever any fire occurs, it shall be the duty of such fire marshal or his designated representative to be present at the same and advise and act in concert with such officers of police as may be present; and, for preserving order at and during the existence of such fire, and for the protection of property, he shall have concurrent powers with the officers of police, and the chief, director, or other officer in charge, but shall not exercise any authority which will conflict with the powers of any chief, director, or other officer in command of any fire department in the discharge of his special duties as such.