(USA TODAY) -- Investigators in California said Oscar-winning actor Robin Williams was found dead in his bedroom, fully clothed, slightly suspended in a seated position with a belt around his neck, with one end wedged between a closet door frame.
At a press conference today, Lt. Keith Boyd, assistant chief deputy coroner for Marin County, Calif., said rigor mortis had already set in. Williams was found by his personal assistant, who broke in to his room when he failed to respond to knocks.
His wife last saw him at about 10:30 pm the night before; she left the house the next day around 10:30 am thinking he was still asleep in his room.
Boyd said some superficial cuts were found on Williams' wrist, and a pocket knife was found nearby. It is being tested to determine if residue on the knife is blood and if it is Williams' blood.
Boyd would not say whether a suicide note was found. Toxicology reports won't be available for several weeks, he said.
The star was found dead at his home in Tiburon, Calif. Monday, leaving Hollywood and the comedian's many fans in a state of shock.
Williams, 63, was found unconscious and not breathing at approximately noon local time, and was pronounced dead shortly after.
Williams' daughter, Zelda, 25, who is shown as a baby in the final post on the actor's Instagram account, tweeted early Tuesday morning, "I love you. I miss you. I'll try to keep looking up."
Robin Williams appears to be have died from asphxia by hanging, according to preliminary findings from the Marin County Sheriff's Office. Investigators believe the Oscar-winning actor committed suicide.
His wife, Susan Schneider, also issued a brief statement on Monday: "This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human beings. I am utterly heartbroken."
Meanwhile, news of Williams' death continued to reverberate throughout the culture, even the world. Some fans reacted today with touching tributes.
Boston fans chalked tributes and the words that Williams spoke in Good Will Hunting around the bench where he and Matt Damon filmed a scene for the movie, creating a singular memorial. Chalk footprints of where Williams sat were drawn on the bench, right above famous quotes from the movie, such as "Your move, chief."
At Los Angeles' Laugh Factory on Sunset Boulevard, the marquee read: "Robin Williams Rest In Peace Make God Laugh."
In Boulder, Colo., where Mork & Mindy was set, fans stopped by the Mork & Mindy "house" to pay tribute.
Many of Williams' co-stars and Hollywood contemporaries expressed their shock and grief, too, via statements and social media.
One constant theme: No matter his demons, Williams was a good guy — warm, sweet, generous, compassionate, humane.
Stage superstar Nathan Lane, who co-starred with Williams in the film La Cage aux Folles, said Williams once made him laugh so hard he cried, and on Monday he cried again at the thought that he was gone.
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"What I will always remember about Robin, perhaps even more than his comic genius, extraordinary talent and astounding intellect, was his huge heart — his tremendous kindness, generosity, and compassion as an acting partner, colleague, and fellow traveler in a difficult world," Lane said in a statement.
Secretary of State John Kerry praised Williams "extraordinary zest."
"Robin wasn't just a huge creative genius, but a caring, involved citizen," Kerry said in a statement. "I'll always be grateful for his personal friendship and his support for the causes that we both cared about deeply."
Alan Alda, in a tribute published on TIME.com, called Williams a "Niagra of wit," adding that his death made him want to do something.
"I hope it makes us all want to do something," Alda wrote."While the whole country, and much of the world, feels this moment of sadness at his death, can we turn the loss of this artist we loved so much into something that pushes back against the ravages of despair?"
"I feel stunned and so sad about Robin," his Mrs. Doubtfire co-star Sally Field told Entertainment Tonight in a statement. "I'm sad for the world of comedy. And so very sad for his family. And I'm sad for Robin. He always lit up when he was able to make people laugh, and he made them laugh his whole life long ... tirelessly. He was one of a kind. There will not be another. Please God, let him now rest in peace."
On the Today show Tuesday morning, Inside the Actors Studio host James Lipton called Williams a "genius."
"His gift ... was genius. Geniuses can do things we have to learn to do. ... You can teach craft, you can teach technique. You can't teach genius. He had genius."
Steve Martin tweeted, "I could not be more stunned by the loss of Robin Williams, mensch, great talent, acting partner, genuine soul."
Sarah Michelle Gellar, who starred with Williams on CBS' The Crazy Ones, remembers her co-star as a friend who became family.
"My life is a better place because I knew Robin Williams," she told People. "To my children he was Uncle Robin, to everyone he worked with, he was the best boss anyone had ever known, and to me he was not just an inspiration but he was the father I had always dreamed of having. There are not enough adjectives to describe the light he was, to anyone that ever had the pleasure to meet him. I will miss him every day, but I know the memory of him will live on. And to his family, I thank them for letting us know him and seeing the joy they brought him. Us crazy ones love you."
Meryl Streep, interviewed by Matt Lauer on Today, called Williams a "generous soul."
"It's hard to imagine unstoppable energy stopped," she said.
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The family of the late Superman actor Christopher Reeve, who was Williams' roommate at Juilliard in the early 1970s, recalled that Williams helped Reeve cope after he was paralyzed in a horse-riding accident in 1995. Reeve died in 2004.
"After our father's accident, Robin's visit to his hospital room was the first time that Dad truly laughed," the family said in a statement to People. "Dad later said, 'My old friend had helped me know that somehow I was going to be okay.' "