Section 1607 - Powers of trustees when vacancies on board exist1. While there is one vacancy in the office of trustee, the two trustees shall have all the powers and be subject to all the duties and liabilities of the three. And while there are two such vacancies, the trustee in office shall have all the powers and be subject to all the duties and liabilities of the three, as though he were a sole trustee.2. When a vacancy shall occur in the office of trustee, the board shall immediately call a special meeting of the district to fill such vacancy.