At midnight, Captain Eldon Walkinshaw handed over watch duties to first mate James A. Morrey.

Emperor ran hard aground on Canoe Rocks, on the northeast point of Isle Royale shortly before 4:15 a.m. on June 4.

Twelve of her crew were killed, while the 21 survivors were picked up by the United States Coast Guard Cutter Kimball.

[1] Despite the success of Merchant, wooden vessels remained preferable to iron ones until the 1880s, due to their lower cost and the abundance of timber.

[2][3][4] In the early 1880s, shipyards around the Great Lakes began to construct iron ships on a relatively large scale.

[12] She was launched into Collingwood harbour on December 17, 1910, as hull number 28; she was christened by James Playfair of Midland, Ontario.

[13] When she was completed, Emperor became the largest Canadian ship built to that date, earning her the nickname "The Pride of Canada".

[12][15][28][29] On June 16, 1911, the Richelieu & Ontario Navigation Company, Ltd. of Montreal, Quebec, acquired a controlling interest in Inland Lines, Ltd.[12]

[13][30][31] Emperor's captain, George Pearson said:I was not on the bast at the time of the accident, the steamer being temporarily in charge of the first mate.

It is usual for a steamer leaving the lock to give a sharp blast, indicating to the canal crew that all is in readiness for the flood.

As soon as the gates were opened the force of the water parted the lines of the steamer, causing her to leave the canal at high speed.

The water at this point was not sufficiently deep to override the anchor, with the result that it was hit by the steamer and tore a hole in her bottom.

[31][34]A court inquiry conducted in Collingwood by Dominion Wreck Commissioner L. A. Demmers determined that the canal employees were to blame for the sinking, as they flooded the lock without checking if Emperor was ready.

[13][34][35] The court further stated that it believed it was "customary for the master of a vessel to sound one blast of the whistle as a signal to the canal authorities to begin flooding", also adding that it "thinks it is extremely necessary that masters of all vessels should have copies of the regulations governing the operation of locks and canals".

[13][34][35] Emperor's officers were acquitted of any wrongdoing, with the blame being placed on a watchman who "happened to be a deck hand, and therefore irresponsible".

[12][38][39][40] On May 4, 1937, Emperor was bound from Port Weller, Ontario, for Hamilton with a cargo of iron ore she loaded in Ashland, Wisconsin.

[12] Conditions on Lake Ontario were foggy, which caused Emperor to miss the port turn, which would then have put her on a course to the piers of the Burlington Canal at the entrance to Hamilton harbour.

[12] After unloading a cargo of coal in Fort William on June 3, 1947, Emperor headed to the Canadian National Railway ore dock in Port Arthur, where she loaded 10,264 long tons (11,496 short tons; 10,429 t) of iron ore from the Steep Rock Mine.

[13][44] At midnight, Walkinshaw handed over watch duties to first mate James A. Morrey, who had supervised the loading of the iron ore.[12][45][42] Shortly before 4:15 a.m., Emperor crashed into Canoe Rocks, on the northeast point of Isle Royale, and broke in two.

[42] The United States Coast Guard Cutter Kimball, which was maintaining navigation lights in the vicinity of Blake Point, intercepted an SOS signal from Emperor and arrived on the scene in 35 minutes.

[16][43][49][52] An investigation carried out by the Department of Transport blamed Morrey, who they claimed "did not keep proper watch", for the sinking of Emperor.

[52][53] They determined that Morrey, who was meant to be on watch duty until 6:00 a.m., was likely sleep deprived at the time of the grounding, and had not made the usual navigational checks Emperor would have required to pass safely between Isle Royale and Passage Island.

[45][53] The courts criticised the prevailing system "which required the First Mate to be in charge of the loading of the ship during the period when he should have been off duty, resulted in his becoming overly tired, suffering as he was from a lack of sleep".

She was also the largest shipwreck to have occurred on Lake Superior since the loss of the freighter Chester A. Congdon in 1918, and the deadliest since the sinking of the canaller Kamloops in 1927, both also at Isle Royale.

[54][62][63][64] The bow section includes two 7,000-pound (3,175.1 kg) anchors, a windlass and chain locker, as well as five relatively intact cargo hatches.

"[71] In order to deter potential looters, the remains were later reportedly sunk at the end of the stern by Canadian divers.

[73] Between 1980 and 1985, Emperor was the second-most popular shipwreck at Isle Royale National Park, behind the excursion steamer America.

[62] However, as of 2009, she is Isle Royale's most frequently visited shipwreck, accounting for over 350 of the 1062 dives made to the wrecks in the park that year.