From the Vancouver Sun (January 8, 1925):

Encumbered by his heavy diving suit and at a depth of 95′ below the surface of the water, Jack Bruce, a city diver, yesterday fought and killed a shark six feet two inches in length which attacked him again and again at the bottom of the Second Narrows. He is back on the job again today. Bruce, who has been employed by the city at the Second Narrows water mains, had another thrilling experience a few days before when a small octopus, about three feet from arm tip to arm tip, wrapped one of its powerful tentacles around his leg. He broke its grip and escaped. Yesterday’s adventure started a couple of minutes after Bruce had reached the bottom. He noticed the enormous fish, not realising at first what it was. Then it made for his legs, and Bruce realised that it was shark. He had an iron bar with him and prodded the fish with it. From then on the struggle became a furious one. Bruce did not dare to pull his signal cord so that he would be pulled to the surface for fear the shark would seize him by the leg. Again and again the shark circled around and made sudden dashes for Bruce. Apparently, Bruce’s defensive tactics angered it for it became more and more vicious. Finally Bruce’s stabs with the iron bar took effect and he killed the shark. Then he attached the remains to a line and had the body of his antagonist hauled to the surface at the same time he went up. Bruce was exhausted by his struggle and did not go down again yesterday. But today he was fully recovered and was again on duty, making another descent. The battle lasted about 30 minutes.

Assessment: Based on the reported size and location, and if the account of the battle is true, the shark could have been a bluntnose sixgill (Hexanchus griseus) or a Pacific sleeper shark (Somniosus pacificus), both of which are relatively slow-moving and known to frequent the area. It would be unlikely for anyone, let alone a diver wearing a cumbersome and highly restrictive hardhat outfit, to fight with and beat to death a salmon shark (Lamna ditropis) or a white shark (Carcharodon carcharias). A white shark would also have been out of season. The Pacific spiny dogfish (Squalus suckleyi), a.k.a. mud shark, does not grow to 1.8 m (6 ft). A so-called mud shark was caught² the same year and exhibited at the Vancouver Yacht Club, on December 9, 1925. The two-metre shark was observed swimming at the surface where it was caught with a boat hook by the club caretaker. Again, the physical and behavioural description of this shark does not match the spiny dogfish, but more closely resembles that of the Pacific sleeper shark which is relatively easy to capture at the surface using a harpoon or gaffe. It is thus our determination that the animal in question may have been a bluntnose sixgill shark or a Pacific sleeper shark but the details of the incident may have been exaggerated for effect.

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References:
¹ Diver Wins Fierce Battle With Shark. Vancouver Sun. 8 January 1925
² Big Mud Shark Caught In Harbor. Vancouver Sun. 10 December 1925