G U A T E M A L A C I T Y, Sept. 4 — Doctors reattached three fingers to the hand of a a 16-year-old pop singer, after they were severed by a helicopter rotor as he waved to fans. Ricardo Abarca was getting off the aircraft at a Guatemala City airport on Saturday. In raising his hand to greet fans, he put it into the still-whirling rotor."The index finger and middle finger are completely recovered," surgeon Gustavo Lopez said Wednesday. "We only have some problems with blood circulation in the little finger."Abarca, who had only recently...