Detectives said that Rosenberg was found dead about 10:30 a.m. on the floor beside the bed in Room 425 of the hotel at 18th Street and the Parkway.
Investigators reported late yesterday that Rosenberg had left a suicide note and three tapes on which he had recorded messages - one for Rivers; one for his daughter, Melissa, who recently finished her freshman year at the University of Pennsylvania, and one for his business manager, Thomas B. Pileggi, a prominent real estate developer from Montgomery County.
A spokesman for the Philadelphia Medical Examiner's Office said last night that an autopsy by acting Medical Examiner Robert Catherman determined that
Rosenberg died of an "overdose of prescribed sedative medication." There was no immediate ruling on the manner of death, the spokesman said.
Rivers was told of her husband's death at the couple's home in Bel Air, Calif., according to her spokesman.
"Rosenberg, who suffered a major heart attack in October 1984 and underwent quadruple bypass surgery, has been in poor health recently and greatly depressed," said a statement issued on Rivers' behalf.
The statement said that Rosenberg had been hospitalized for gastrointestinal bleeding last week while on a trip to Ireland and that he had been scheduled to return to the Los Angeles area last night to be admitted to Cedars-Sinai Medical Center.
After the autopsy, Rosenberg's body was picked up late last night by the John B. McIlvaine Funeral Home, of the 3700 block of Midvale Avenue, investigators said.
Police and hotel officials handled the discovery of the body with utmost discretion. Guests of the hotel, where an official said the average room charge is $180 per night, saw no ripple in the placid routine.
Even in the hallway outside Room 425, the only sign of anything untoward was a steel table on which police had wheeled up stereo equipment to listen to what was on the tapes.
A police van had pulled up to the loading dock behind the hotel.
Rosenberg's body was removed from there.
"We have no statement to make," said Karl Heizmann, the hotel's executive manager. "And we have been asked by a close friend of the family to direct inquiries to him."
That was Pileggi, who police said had alerted hotel officials to check on
Rosenberg after he called the room and received no answer. He was at the hotel with police later in the day but declined to comment to reporters.
Pileggi and the Rosenbergs - Rivers' legal name is Joan Rosenberg - have been involved in numerous real estate developments in Bucks and Montgomery Counties.
"Joan, Edgar and I go way back," Pileggi said in a 1984 interview. "I advise them on what to buy and what not to buy. . . . They want to be in a position where they own a lot of income-producing properties when they retire. A lot of stars have nothing to show at the end."
According to a 1984 article in The Inquirer, the couple at that time had invested about $19 million in Pileggi's developments, including his Justa Farms shopping center and condominiums in Upper Moreland Township, Montgomery County.
The couple also had purchased 16 stores at Warrington Mews Pavilion shopping center in Warrington Township, Bucks County, and a one-third interest in an industrial complex in nearby Horsham Township.
In 1985, the couple donated $25,000 toward a park in Upper Moreland named for Frank J. Pileggi, the developer's late brother.
The group's best-known project is one that remains unbuilt - their independent Borough of Two Ponds on 87 acres in Northampton Township, Bucks County. Local opposition has tied up the project in the courts for years.
Rosenberg was executive producer of The Late Show Starring Joan Rivers until Rivers was dropped in May by Fox Broadcasting Co. The couple had been married 22 years.
In 1984, after Rosenberg's heart attack, Rivers told People magazine: "I was losing everything - my best friend, the only stability in my life, the only person I totally trusted, my rock. Suddenly I realized that I drew all my strength from Edgar."