A 21-year-old American student was stabbed to death in Rotterdam, allegedly by her roommate, police confirmed Friday. According to a police statement, authorities received reports of a quarrel at an apartment on Kralingse Kerklaan on Wednesday. When they entered the apartment, the statement said, police found Sarah Papenheim with stab wounds and attempted to resuscitate her. Police say those attempts were unsuccessful, and she died of her injuries. An investigation led authorities to the suspect, Papenheim's 23-year-old roommate, who was arrested at the Eindhoven train station, the police statement said. The two lived in the same apartment with their own...