In June 1942 the ship was transporting Army cargo and troops from Kingston, Jamaica to San Juan, Puerto Rico when torpedoed and sunk by U-172 with loss of 46 of the 77 persons aboard.

[7] Sicilien was one of four similar cargo ships in commercial service for Det Forenede Dampskibs Selskab (DFDS), Copenhagen, operating between northwest Europe and the Mediterranean.

[8] After war began in Europe Sicilien and the three other new ships Tunis, Marocco, Algier were put into Atlantic service.

[5] Sicilien was the main transport for establishment of an air ferry route that would allow shorter range aircraft to fly from Newfoundland to Scotland by way of Greenland and Iceland.

The sites were accessible only with smaller vessels and extreme caution was required due to poor charts, ice, snow and tides up to 42 ft (12.8 m).

Sicilien made a stop at Halifax, Nova Scotia picking up five trawlers and three Norwegian vessels for the mission.

[13] Sicilien transiting unescorted from Kingston, Jamaica to San Juan, Puerto Rico with Army personnel was torpedoed and sunk on 7 June 1942[note 4] by Germany's U-172 about 10 nautical miles (19 km) south of Cape Beata, Dominican Republic (17°30′N 71°20′W / 17.500°N 71.333°W / 17.500; -71.333).

[5][14][6][15] In 1958 the United States offered Denmark $5,396,202 in settlement of claims for use and loss of all forty vessels including Sicilien.