Day by day, Eleanor Connelly Coon was growing weaker from a wasting disease that was destroying her coordination and her mind. But Denby Coon clung to hope and a tradition of occasionally bringing her a single long-stemmed red rose for the sweet delicate scent she enjoyed.

Just the other day, his own back throbbing with pain, Coon had stopped by a neighbor's garden to pick one more for his wife -- a former fashion model he married 42 years ago. But then the hope and the tradition died.

Last Friday came the word that Coon, 71, had placed the barrel of a .45-caliber pistol to the head of the 78-year-old woman he lovingly called "Mama" and pulled thr trigger.

After calling Prince George's County police and describing the shooting, Coon killed himself, police said. They found several farewell notes addressed to close friends and relatives.

"It is one of the saddest homicide-suicides we've ever seen," said Sgt. Robert Law, of the county police. "Mr. Coon told his friends in the notes that he'd been unsuccessful in his effort to find a nursing home where both he and his wife could receive proper care."

"Coon's doctor told him recently that [Coon] needed to go to the hospital for 10 days to be treated for his back ailment," Law added. "He didn't believe his wife would get proper care in a nursing home if she were there alone."

Until the end, the Coons -- who had no children and kept to themselves -- had been in love, according to friends and neighbors.

"I've never seen a husband who worshiped his wife more," said Helen Chaney, a personal friend of the couple and resident manager at the Marlow Heights apartment complex where the Coons lived for 13 years. "He worshiped the ground she walked on. They held hands when they were walking. He opened doors for her. When it became difficult for her to get around, he used to carry her out to the car so that she could get out of the apartment and go for a ride in the country."

According to friends and relatives, Coon, a native of Thomasville, Ga., who lived with his wife in Southeast Washington for 40 years, retired from the postal service in the 1960s, then worked part time as a pallbearer and limousine driver for a funeral home, and as a real estate agent.

Eleanor Connelly Coon, born in Colonial Beach, Va., did some fashion modeling in the early years of the marriage, friends said.

In recent months, Coon was increasingly unable to communicate with his wife, who suffered from Alzheimer's Disease, an ailment that results in mental and physical deterioration. And friends who saw him last say that Coon -- a man who usually chose to suffer without complaining -- was now telling how unbearable his own back pains were.

"I talked with him last Thursday," Chaney said. "He said the pain in his back was so bad it was almost unbearable -- he couldn't sleep at night."

Barbara and Jerry Fox, who said they knew the Coons for 10 years before moving to Kissimmee, Fla., last April, talked with Denby Coon by telephone two weeks ago. "He said he'd hurt his back and that the pain was getting worse," said Barbara Fox. "We invited them to come to Florida and spend the winter with us. He seemed excited about the idea, but he kept saying he didn't think his wife would be able to make it."

"They never had a negative or cross word for anyone," said Candace Pyles. Her husband, Robert, Eleanor Coon's grandnephew, was designated executor of the couple's estate in one of the final notes. "They kept their problems to themselves and they did what they could to help others."

"They lived a very modest life," she added. "They required very little to live. But life for them was meaningless without each other."

That pattern is a familiar one, according to Calvin Frederick, director of the Disaster Assistance and Emergency Mental Health office at the National Institutes of Health. "As some elderly people begin to lose their health and move closer to the time when they might have to live in a nursing home, they feel useless, not needed and not worthwhile.

"Their circle of friends grows smaller and to lose one is a traumatic experience for them. They feel that suicide is the only way out."

That way, Denby Coon's way, will be chosen by about 1,300 other men and women between the ages of 70 and 74 this year, according to experts on aging.

Among the notes Coon left were detailed instructions to his grandnephew outlining how his estate was to be handled. And there was a note of appreciation to the resident manager.

"The note just said how glad he was that he'd been able to live here," Chaney said. "He said he and his wife appreciated all we'd done to make them comfortable. And he said he was sorry he had to leave this way."