Joan Rivers Dead at 81: Inside the Comedian's Close Relationship With Her Daughter Melissa Rivers

— -- Joan Rivers' daughter, Melissa Rivers, has been the other half of the successful show "Joan & Melissa: Joan Knows Best?" for the past four years and the co-creator of her mother's YouTube series "In Bed With Joan" -- and has hosted a variety of red carpet specials with her mom over the years and served as a producer for Joan's shows on E!

But Melissa Rivers, 46, was more than just a co-worker to Joan Rivers, who died on Thursday at the age of 81.

After spending the whole week by her mother's side after the comedian arrived at Mount Sinai Hospital in New York City Aug. 28 in cardiac arrest, Melissa Rivers said in a statement today, "It is with great sadness that I announce the death of my mother, Joan Rivers."

Melissa Rivers had been updating fans as to her mother condition and thanking them for their continued support. She added in a statement after her mother's death that the comic legend was "surrounded by family and close friends" when she died.

Read: Joan Rivers Dead at 81

Read: Joan Rivers Hospitalized After Cardiac Arrest

Joan and Melissa Rivers have built such a close bond in recent years that the late comedian told the Wall Street Journal in March that for the past four years, she's been staying in her daughter's guest room, a converted garage, in the Pacific Palisades area of Los Angeles. The home was the set for her Web series.

"For the past four years, I've been flying out from New York and staying a few days each week to tape our two reality shows. My room is down a flight of stairs. You really learn your place here fast," Joan Rivers joked to the newspaper.

It wasn't just Melissa Rivers who reaped the benefits of having her mother stay with her when she came to visit. Melissa Rivers' son, Cooper, became close with his grandmother.

"Cooper, who just turned 13, has an amazing relationship with my mother. Those two are always deep in cahoots against me. He knows which one to go to," Melissa Rivers said.

In a 2012 episode of "Joan & Melissa," viewers got a heartfelt look into just how close that bond between mother and daughter grew over the years.

"If anything happens, Melissa," Joan Rivers told her daughter just before another plastic surgery procedure, "I've had a great life. If I died this morning, nobody would say 'so young.' You're a terrific person, Cooper's fine. ... I've had an amazing life, if it ended right now -- amazing life! You've been wonderful and we've had a great ride together."

Melissa Rivers would hear none of that talk from the mother she loved dearly.

"You don't like to feel like people like you or care about you or want you around," she told her mother, making it obvious she wanted her around.

Joan Rivers continued to impress on her daughter she was more interested in praising her daughter then herself.

"You've been just great and you've come through so much, and how lucky we are," Joan Rivers said. "I love you so much."

But the bond between Joan and Melissa Rivers didn't come without its trials and tribulations.

Melissa Rivers is the daughter of Joan Rivers and Edgar Rosenberg, who committed suicide in 1987. Joan Rivers told People magazine in 1993 that "Melissa blamed me."

Melissa Rivers added in a group interview with the magazine about the dark times, "I didn't want to know [what my mother was feeling]. It was her problem. I was going through my own thing."

Three months after her father's death, Melissa went through an abusive relationship and it was her mother who was right there for her during one of her lowest low points. It was the beginning of the bond you see today.

"The thing I had and will always have is my mother. She was right there for me," Melissa Rivers said. "She didn't condemn me. She never asked me, 'How could you have gone back to him?' She just said, 'OK, this is the situation. Let's deal with it.'"

"We had to go through the bad times, but we came out of them," Joan Rivers said. "Melissa is the one to whom I could give total affection and feel it being absorbed and returned."