Steep Rock Mine (Atikokan, Ontario, 00/08/1943): HASs from edge of pit, level shots of power shovel, heavy duty trucks moving to and fro in open pit mine, leisurely activity. Shot of men wielding picks at entrance of mine. Shot of men wielding picks as seen from inside of tunnel, silhouetted against bright light. Shot of men being allotted each a crate of dynamite. LAS of man standing on edge of pit giving signal for blast (no shot of blast). LAS of man giving series of signals. MCS of stop watch in man's hand. Two shots of trucks, power shovel at work in pit. Cut to small explosion in water. HASs of water flowing past camera. Canted shot of man pressing on plunger (no shot of explosion). HASs of Steep Rock Mine buildings. PAN along pipeline disappearing under water of river. Shot of water flowing rapidly from open pipes. Shots of test drill rigs. Cut to tail end of explosion opening up channel, water beginning to flow through in volume. Two closer shots of madly rushing water.