24. Whenever the Engineer shall be of opinion that any delay in the execution of any act or work specified in section 7 would be attended with grave danger to life or property, he may forthwith execute or cause to be executed such act or work: Provided that he shall without delay prepare or cause to be prepared the estimates, specifications and plans of such act or work together with a copy of the map as provided in section 7, and shall cause general notice to be given that the act or work mentioned therein has already been commenced; and thereupon such proceedings and inquiries shall be had as in and by Part II of this Act are directed.