While some people think flying a helicopter is dangerous work, just standing on a Manhattan sidewalk proved to be the most dangerous thing that Paul Smith ever did. Smith, who had flown for WABC-TV New York for many years, was killed Sunday evening as he and several family members were leaving a restaurant and an out-of-control taxi went up onto the sidewalk and hit them. Smith, age 60, was dead at the scene. His wife, Donna, and a seven-year-old boy from Oklahoma were the most seriously hurt of several people who were injured. At last report, the cab driver had not been charged.