When facts are presented to the board, or to any member thereof, tending to show that an unreasonable hazard exists in the continued operation of a tramway, the board or member, after such verification of said facts as is practical under the circumstances and consistent with the public safety, may, by an emergency order require the operator of said tramway forthwith to cease using the same for the transportation of passengers. Such emergency order shall be in writing and notice thereof may be served by any person upon the operator or his agent immediately in control of said tramway by a true and attested copy of such order, the return of such service to be shown by an affidavit on the back thereof. Such emergency order shall be effective for a period not to exceed 48 hours from the time of service. Immediately after the issuance of an emergency order hereunder, the board shall conduct an investigation into the facts of the case as contemplated in N.H. Rev. Stat. § 225-A:19, and shall take such action under said N.H. Rev. Stat. § 225-A:19 as may be appropriate.