North Carolina General Statutes Chapter 58. Insurance § 58-80-40. Municipalities not to be left unprotected

At no time shall the entire personnel or equipment of any municipal fire department be absent from the municipality in response to a call to another municipality, or other place lying at a distance exceeding two miles from the corporate limits, but there shall remain within the municipal limits such personnel and equipment as in the judgment of the local fire chief might provide sufficient protection during the absence of the remainder.