GRAVESEND - An elderly woman was struck and killed by an ambulette in Gravesend.Witnesses say it appeared the 75-year-old woman was on her way out of Kelly Memorial Playground when a vehicle from Ambulette Star Trans hit her near the intersection of Avenue S and East 15th Street.Police say the 36-year-old driver remained on the scene and won't face any charges.News 12 Brooklyn called Ambulette Star Trans, but the person who answered the phone refused to comment.