[6] On September 9, 1910 while bound from Ludington for Milwaukee with 62 passengers and crew and 29 rail cars filled with general merchandise and coal, Pere Marquette 18 began taking on massive amounts of water.

As none of her officers survived to recount what happened, the true cause of Pere Marquette 18's flooding remains a mystery.

[9][10] Pere Marquette 18 (Official number 150972) was designed by Robert Logan and was built in 1902 by the American Ship Building Company of Cleveland, Ohio.

[3][4][5][6] She received her first enrollment in Cleveland, Ohio on July 19, 1902; her initial home port was Saginaw, Michigan.

[16][5][6][14][15] On November 4, 1903 Pere Marquette 18 rescued the crew of six from the sinking schooner barge A.T. Bliss, which while bound from Sturgeon Bay, Wisconsin for Ludington broke loose from the tug Sidney Smith.

[3] In 1909, Pere Marquette 18 was chartered by the Chicago and South Haven Steamship Company for service as an excursion steamer between.

At around 3:00 A.M. (some sources state 4:30 A.M.) on September 9, while about halfway across Lake Michigan, the helmsman of Pere Marquette 18 began complaining that she wasn't steering properly.

[6][20][19][14] At about the same time, an oiler who went to oil the propeller shaft bearings reported to the bridge that there was approximately 7 feet (2.1 m) of water in her stern.

[6][21][15] Captain Kilty eventually ordered that the course to be altered to Sheboygan, Wisconsin, and that 9 (some sources state 4 or 13) rail cars be jettisoned.

[6][19][15] At around 5:00 A.M. by orders of Captain Kilty, purser and wireless operator Stephen F. Sczepanek (or Sczepanck) sent out the CQD: "Car ferry No.18 sinking - help!, which was repeated continually for nearly an hour.

It was also suggested that during Pere Marquette 18's conversion back to a ferry, one of her seacocks was accidentally left open, causing water to flood in.

[25][26] The Marker reads:At least twenty-nine persons died when this vessel sank in Lake Michigan twenty miles off the Wisconsin coast on September 9, 1910.

All of the officers and many of the crew and passengers perished, among them the first wireless operator to die in active service on the Great Lakes.

The S.S. Pere Marquette 17, aided by other ships who also heeded the wireless message for help, rescued more than thirty survivors but lost two of her own crew.

[25] On July 23, 2020 wreck hunters Jerry Eliason of Cloquet, Minnesota and Ken Merryman of Fridley, Minnesota were searching for Pere Marquette 18 using a side-scan sonar and an archived account from the United States Life-Saving Service; they eventually located an anomaly in the middle of Lake Michigan, roughly 10 hours into their search.

[9][10][11][27] The following day, Eliason and Merryman went back to the anomaly and dropped a camera attached to a 1,000 feet (300 m) cable down to it, discovering the bow of a ship rising off the lake bottom; they confirmed the wreck was Pere Marquette 18 based on a comparison of the davits of the wreck and the davits of Pere Marquette 18 in historical photographs.

[10][11][27][28] Due to bad weather, it took Eliason and Merryman three weeks to return to the wreck, in order to capture footage of it.