Section 4
SEC. 4. If the grantees shall not commence the manufacture of ice in any of the municipalities of General Santos, Koronadal, Surala and Tacurong, Province of Cotabato, within one year From the approval of this Act, unless prevented by an act of God or force majeure, martial law, riot, civil commotion, usurpation by military power or any other cause beyond the grantees' control, this franchise shall become null and void.