DAYTON DAILY NEWS                   Copyright (c) 1994, Dayton Newspapers Inc.DATE: Monday, December 12, 1994              TAG: 9412120103EDITION: CITY           SECTION: NEWS        PAGE: 1A TYPE: MAJOR  SOURCE: By Benjamin Kline  DAYTON DAILY NEWS                        'THERE IS A REASON FOR THIS'    Virginia W. Kettering, daughter-in-law of the great engineer, said Sunday she was told of the fire Saturday night by friends, but chose not to visit theblazing hilltop near her own home.    "I could not see the flames, but I could see the flashing lights," Mrs. Kettering said. "I felt that in these circumstances, and with the firefighterstrying to do their job, the fewer people up there, the better."    Loss of the house, where she and her late husband, Eugene, lived for 10 years, was devastating.   "I was up until 4 a.m. I couldn't sleep. I couldn't feel any worse than I do now," Mrs. Kettering said Sunday. Yet the 88-year-old philanthropist tried to look to the future, a characteristic stance she often takes in community affairs:   "All good things must come to an end," Mrs. Kettering said. "Oftentimes there is a reason for these things, I'm trying to tell myself, " she said, then paused. "There is a reason for this; that something will come of it, evenmore helpful."   Although she grew up in the old Harshman mansion east of Dayton, Virginia Weiffenbach Kettering spent countless hours at Ridgeleigh Terrace over the past 63 years. She married Olive and Charles Kettering's only child, Eugene, in 1931.    After Charles Kettering's death at Ridgeleigh Terrace in 1958, Eugene and Virginia Kettering returned to Dayton from Hinsdale, Ill., and made the mansion home for themselves and grown children, Susan, Jane and (the late) Charles F. Kettering II.   The couple extensively remodeled the stone-trimmed Tudor-style house, adding an extensive Japanese garden and tea house in 1960. A large terrace wasenclosed to create what Mrs. Kettering called a lanai, a large family gathering room.    But they preserved Ridgeleigh Terrace's special features, including dark teakwood paneling, cast-plaster ceiling ornament, a pipe organ that Charles Kettering bought for Olive, and the air-conditioning system that Charles designed - the first in an American house.    "It was a very interesting house, all the way through," she said. "But it was built to be a home, and it was a home for my family and grandchildren."    That means fond memories for Mrs. Kettering's nine grandchildren and 17 great-grandchildren, she said.    Eugene Kettering died in 1969 and his widow gave the property to Kettering Medical Center in 1973, "acres and acres and acres on both sides of the road,"she said. The couple earlier had funded the hospital with a large endowment. Documents in a recent court case showed the family's gifts to the institution have exceeded $17 million.    A spokeswoman for Kettering Medical Center said this was to have been Mrs. Kettering's first Christmas with her family at the mansion in several years. In preparation, the house had been spruced up, including having carpet sent tothe manufacturer and rewoven.    The preparations were complete by last week, when there were two special events attended by Mrs. Kettering, the spokeswoman said.    Mrs. Kettering said she expected to meet with hospital officials about the fire, but she acknowledged, "There is nothing to work with. It's gone."