Some 15 people have been injured in a serious accident involving a tractor in the southern German state of Bavaria, police said on Sunday. The tractor was pulling a trailer in the village of Hartenstein near the city of Nuremberg when it overturned, leaving the 29-year-old driver seriously injured and a 26-year-old passenger in a critical condition. An 18-year-old passenger on the trailer also suffered serious injuries, while 10 others were taken to hospital as a precaution with minor injuries. A police spokeswoman said the tractor was travelling on an unpaved road on its way to a church fair …