The search is on for a driver who police say hit and killed a Bronx great-grandfather Wednesday. According to police, 70-year-old Henry Mc Kenzie was struck while crossing Southern Boulevard and East 183rd Street. Residents in the area say speeding cars make the intersection extremely dangerous to cross. They also say the traffic light changes too fast and does not provide enough time for pedestrians to cross the street safely. Officials from the Department of Transportation say the latest fatality is the only accident that happened at the intersection this year. They also say the traffic light is timed to give pedestrians 31 seconds to cross the street at night and 43 seconds during rush hour. Meanwhile, police are asking anyone with information on the accident to call 1-800-577-TIPS.