2014 Event Swedish officials release a photo of U-boat tracks along the sea floor as proof that a foreign submarine breached the nation�s waters; the search began after the military detected Russian-language distress calls and spotted an unidentified vessel 1994 Event Serbian army bombs distress clinic in Goradze Bosnia, 28 killed 1909 Event Liner "Arapahoe" is 1st ship to use SOS distress call 1904 Event Marconi Co establishes "CQD" as 1st International radio distress signal 1885 Event General Wolseley receives last distress signal of General Gordon in Khartoum
