SOUSSE, Tunisia: Ten years after a beach attack that killed 30 Britons and delivered a crippling blow to Tunisia’s tourism industry, European holidaymakers are finally returning in what authorities hope will be record-breaking numbers. In June 2015, a Tunisian university student slipped a rifle out of a beach umbrella and opened fire on vacationers outside a hotel in Sousse, about 140 kilometers (90 miles) south of the capital.