Starbucks Korea operator SCK Company has swung to an operating loss in the second quarter, following a controversial promotional event that drew nationwide criticism for allegedly insulting victims of the bloody crackdowns on major pro-democracy uprisings in the 1980s, prompting some consumers to launch boycotts. During an earnings call Thursday, Emart, which operates SCK Company, said the coffee chain posted an operating loss of 18.4 billion won ($13 million) in the second quarter, swinging from 40.3 billion won of operating profit a year earlier. During the same period, net sales declined 6.1 percent to 747.3 billion won. The company attributed the loss to the absence of its Summer Frequency promotional event in June, but did not cite worsening consumer sentiment toward the brand or boycott attempts as factors. Starbucks Korea came under fire after it launched a promotion campaign for its tank-style tumblers, designating May 18 as “Tank Day.” The date marks the anniversary of the 1980 Gwangju uprising, when pro-democracy demonstrators were brutally suppressed by military forces us