The SS Schenectady was a T2-SE-A1 tanker built during World War II for the United States Maritime Commission.

[2] On 16 January 1943, she was moored at the fitting dock at Swan Island, in calm weather, shortly after returning from her sea trials.

The cracks reached down the port and starboard sides almost to the keel, which itself fractured, jackknifing upward out of the water as the bow and stern sagged to the bottom of the river.

This was not the first of the war-built merchant fleet to fracture in this way – there had been ten other major incidents, and several more would follow – but it was perhaps the most prominent; it occurred in full view of the city of Portland, and was widely reported in the newspapers even under wartime conditions.

[3] The cause of the fracture was not fully understood at the time; the official Coast Guard report gave the cause of failure as faulty welding, while the Board of Investigation considered factors as diverse as "locked-in" stresses, sharp changes in climate, or systemic design flaws.