The grim details of the death of comedian and actor Robin Williams were released Tuesday as flowers piled up at makeshift memorials and his children and ex-wife issued heart-wrenching statements about a "gentle, kind" man who seemingly had everything but inexplicably decided to hang himself.

Williams' three children - Zachary, 31, Zelda, 25, and Cody Williams, 22 - echoed the sadness and confusion experienced across the nation, saying they felt "stripped bare" and are struggling to cope with the apparent suicide.

"I lost my father and a best friend and the world got a little grayer," said Zak Williams. "I will carry his heart with me every day. I would ask those that loved him to remember him by being as gentle, kind and generous as he would be. Seek to bring joy to the world as he sought."

Williams' children said their time with their father was precious.

"My family has always been private about our time spent together," said Zelda Williams. "It was our way of keeping one thing that was ours, with a man we shared with an entire world. But now that's gone, and I feel stripped bare. My last day with him was his birthday, and I will be forever grateful that my brothers and I got to spend that time alone with him, sharing gifts and laughter."

Marin County sheriff's Lt. Keith Boyd, the assistant chief deputy coroner, said there was no evidence of foul play in the death of the 63-year-old performer who was beloved for his rat-a-tat delivery and warm personality, but who had struggled with cocaine and alcohol addiction and severe depression.

The grim details

Boyd said Williams was last seen alive at 10:30 p.m. Sunday when his wife, Susan Schneider, went to bed. His personal assistant became concerned about 11:45 a.m. Monday, Boyd said, after Williams failed to answer knocks at his door.

The assistant eventually managed to open the door and found Williams clothed, in a seated position and "with a belt secured around his neck, with the other end of the belt wedged between the clothes closet door and the door frame," Boyd said. "His right shoulder area was touching the door, with his body perpendicular to the door and slightly suspended."

Williams was "cold to the touch," Boyd said, and rigor mortis had set in. Forensic scientists say it takes three or four hours for rigor mortis to begin after death.

Investigators found superficial cuts on the inside of Williams' left wrist, and recovered a pocketknife with its blade closed and what looked like dried blood on it, Boyd said. The cause of death was "asphyxia due to hanging," according to preliminary results of an autopsy. Williams' children did not mention their father's depression or his struggles with chemical dependency, but Zelda made reference to dark times and an inability to find peace.

"He was always warm, even in his darkest moments," she said. "While I'll never, ever understand how he could be loved so deeply and not find it in his heart to stay, there's minor comfort in knowing our grief and loss, in some small way, is shared with millions. It doesn't help the pain, but at least it's a burden countless others now know we carry."

'Never be the same'

Cody Williams said there are "no words strong enough to describe the love and respect I have for my father." He expressed hope that he would see him in the afterlife.

"The world will never be the same without him," he said. "I will miss him and take him with me everywhere I go for the rest of my life, and will look forward, forever, to the moment when I get to see him again."

Williams' ex-wife, Marsha Garces Williams, the mother of Zelda and Cody, said she has been comforting her children "as we attempt to grapple with celebrating the man we love, while dealing with this immeasurable loss."

Outside the Tiburon home, dozens of television crews gathered Tuesday, including from stations in Brazil, Japan, Norway and England.

The stream of mourners included several children, who in many ways might be the most affected by the death of an actor who welcomed trick-or-treaters on Halloween and was beloved for youthful antics and quirky movie characters.

A somber Brandon Antonio, 13, dropped off flowers after being driven to the home by his father. "My favorite movie was 'Jumanji,' " Brandon said. "That was a really great one."

The Williams family expressed gratitude for the outpouring of support from the public and the expressions of sympathy.

"To those he touched who are sending kind words, know that one of his favorite things in the world was to make you all laugh," Zelda said. "Dad was, is and always will be one of the kindest, most generous, gentlest souls I've ever known, and while there are few things I know for certain right now, one of them is that not just my world, but the entire world is forever a little darker, less colorful and less full of laughter in his absence. We'll just have to work twice as hard to fill it back up again."

Peter Fimrite, Evan Sernoffsky and Henry K. Lee are San Francisco Chronicle staff writers. E-mail: pfimrite@sfchronicle.com, esernoffsky@sfchronicle.com, hlee@sfchronicle.com Twitter: @pfimrite, @henryklee, @evansernoffsky