NEW ORLEANS - Mayor Ray Nagin asked the governor Monday to send National Guard troops to patrol his city after a violent weekend in which five teenagers were shot to death. City leaders convened a special meeting to voice outrage after the killings Saturday in an area near the central business district. "If we don't have wind knocking us down, we have shooters knocking us down, and that's unacceptable," said City Council President Oliver Thomas. The shootings brought this year's murder toll to 52, raising fears that violence was back on the rise in a city that had been plagued...