She apparently had fallen asleep after a night out alone that included a visit to the Central Bar & Grill near her home, where she was a regular.
Stern this morning devoted the first 25 minutes of his controversial show to her death.
"We're very saddened today . . . because she was a nice lady. She was a new friend. I feel terrible for her," Stern said on WYSP, which carries his show here.
A spokeswoman for WMMR said that John DeBella would be off his morning show, which runs opposite Stern's, for the immediate future. His recently hired co-star, Howard Eskin, was joined this morning by DJ Pierre Robert.
A Central Bar & Grill employee said he had seen Annette DeBella early on the morning of her death, and she did not appear to be drunk.
She left Central sometime after 1 a.m. and stopped at a convenience store on her way home. A bag of groceries was discovered on the palomino-colored leather upholstery next to her body.
The car engine was still running around 5 a.m., when she was found by Jack Godwin, a tree surgeon who lived with her. Godwin is the brother of Pat Godwin, DeBella's musical side-kick on his morning radio show.
Another morning-show sidekick, Grover Silcox, said yesterday that John had known about the relationship between Jack and Annette, but "he never seemed to react to that very much."
Annette DeBella was pronounced dead at Bryn Mawr Hospital at 5:46 a.m. There were "no signs of suspicious circumstances," Lower Merion police said.
Police said yesterday the death appeared accidental.
John and Annette met in a South Street rock club in 1982, shortly after DeBella arrived at WMMR from his native Long Island. She was born in North Carolina, where she lived for 10 years, before moving to this area, where, as an adult, she worked in an office and became a fixture on the local music scene.
They were married in September 1986 at a glittering affair at the Academy of Music, which was catered by La Truffe.
It seemed that Annette, the young girl from North Carolina, had arrived.
Just before meeting DeBella, she was at the end of a five-year live-in relationship with Mikey Snyder, drummer with the local band the A's.
Her friends agreed that Annette liked "the scene," liked musicians and liked celebrities. They agreed that she was fun to be around. Some said she liked to drink bourbon.
In January, the DeBellas separated. Although they both denied it until the spring of this year, some had seen trouble in their marriage well before.
"The last time I saw them together, three years back," said a local musician, "the bloom was off the rose. Before that, they were disgustingly happy, like a David Niven movie."
One bone of contention might have been children.
DeBella, 42, wanted children, said one friend of Annette's, but Annette changed the subject when he talked about it. "What are you waiting for," the friend asked Annette, "to fall in love with him?"
Annette DeBella told me in an exclusive interview last month that she felt she was getting no respect from her husband even early in the marriage.
"I was his little showpiece. I was his PR girl," she said. "Especially at the beginning. That's why I stopped going places with him, because I did not want to be treated like, here's my little wife, she'll entertain you while I walk around and do my thing. I totally stopped going to functions."
She said she felt that she never really had a husband.
"John got up at 4:30 in the morning. I tried a few times to get up with him, to have a cup of coffee with him," she said.
" 'Oh, no, that's my private time. That's my thinking time. I need that time by myself,' " she quoted him as saying.
John DeBella, who was looking at funeral plots yesterday, declined to comment and issued a statement: "I was devastated to learn of my wife's death. Despite our recent differences, we shared many happy and loving times together. It is a terrible loss and her family and I share it with the many people who knew her and loved her."
Friends of the couple say that DeBella remains on good terms with his mother-in-law, who lives in South Jersey, and helped comfort her on Saturday after Annette DeBella's death.
The funeral will be private and no death notice was placed, partly, according to a spokesperson, out of fear that some Stern fans might disrupt the services.
The two jocks were involved in a longstanding rivalrly that began when Stern came into the Philadelphia market in 1986 and declared he would end DeBella's reign as the top-rated morning radio-show personality.
That happened four years later, but the feud continued, becoming more bitter each year. The drama recently culiminated in some of the biggest headlines Annette DeBella ever made: when she went on Stern's show.
Just Friday, Stern announced on WYSP, which carries his show here, that he was marketing a videotape of a "date" Annette had with a local Stern fan who uses the name of Captain Janks, but who is actually Tom Cipriano.
WMMR recently revamped DeBella's solo show by adding Eskin as a co-host on Oct. 5.
Eskin said last night he had spoken to DeBella, who "was kind of broken up about it, obviously.
"I asked him how could it happen, and he said she had a habit of closing the garage door before she turned off the car. He said, 'I always told her about that, but she always did it.' "