At least 13 people were killed and 30 others injured when a bus carrying retirees overturned on a foggy road in Argentina, media reported.According to the police, the incident took place around 10:00 a.m. on Monday at the intersection of the highways 157 and 308 near the city of La Madrid in the northern province of Tucuman, reported Xinhua news agency.More than 30 ambulances transported the victims to different hospitals and four groups of firefighters collaborated with the rescue tasks.