Gardai in Dublin are appealing for witnesses to a fatal road accident early yesterday at Howth Road in Killester. A pedestrian in his 50s was killed after being hit by at least one vehicle. He was taken to Beaumont Hospital, where he was pronounced dead. Gardai have interviewed the driver of a car which stopped at the scene. However, they believe other vehicles may have been involved in the incident, which occurred near a Texaco station on the road at about 12.30 a.m.