Dernatta (Sis) Sullenberger Knox of 223 Main St.;Belle Vernon died Tuesday March 24;1987;at 2:30 p.m. in Mon Valley Hospital. She was 64. Mrs.Knox was born March 10;1923;in Star Junction;a daughter of the late Robert L.and Gladys Quinn Sullenberger. A resident of the Belle Vernon area the past 30 years;she was Protestant. Mrs.Knox was a member of the Ladies Auxiliary of Belle Vernon Fire Department No.2. In addition to her parents she was preceded in death by her husband;John E.Knox;Nov.21;1979;two sisters;Leona;1930 and Alice;1934;two brothers;William F.Sullenberger;1984 and Floyd Sullenberger;1926;and by a step-sister;May Teegaroen. Survivors include one daughter;Mrs.Russell (Linda) Theakston of Belle Vernon;five brothers;James and Ralph Sullenberger;both of Tampa;Fla.;Charles and Jack Sullenberger;both of Monessen;and Edward Sullenberger of Latrobe;two sisters;Mary Kay Kalakewicz of Belle Vernon and Mrs.Otis (Shirley) White of St.Petersburg;Fla.;four grandchildren and several nieces and nephews. Friends will be received Wednesday from 7 to 9 p.m. and Thursday from 2 to 4 and 7 to 9 p.m. in the Leonard J.Parzynski Funeral Home;626 Broad Ave.;Belle Vernon;where services will be held Friday;March 27;at 10:30 a.m.;with the Rev.Kenneth J.Peters;pastor of the United Methodist Church of Monessen;officiating. Burial will be in Belle Vernon Cemetery. The Leonard J.Parzynski Funeral Home is in charge of arrangements.