Rescuers in Pakistan have pulled a teenager alive from the rubble of a collapsed factory near Lahore 50 hours after the structure toppled,officials said over the weekend.The teenager had been trapped for more than two days after the collapse and his family,thinking him dead, had already identified and buried another recovered body they believed to be to be his.An 18-year-old Muhammad Shahid was also evacuated alive 50 hours after the building collapsed by the blessing of God,Muhammad Usman,a top administration official in Lahore,said.