James Gandolfini Dead at 51 -- Stars React on Twitter

Since the news of his death broke, his "Sopranos" costars and celeb fans have issued statements or taken to Twitter to express their condolences -- giving tribute to the man they call "One of the greatest actors of our generation."

We'll continue to update as more reactions come in:

Drea de Matteo
Fughedabout losing one of the best actors of our time...we lost so much more...anyone from the Soprano family will tell you he was one of the most generous, real and humble human beings ever...with a presence that could shatter planets when he walked into a room. A King through n through. So very sorry for his family.

Edie Falco
I am shocked and devastated by Jim's passing. He was a man of tremendous depth and sensitivity, with a kindness and generosity beyond words. I consider myself very lucky to have spent 10 years as his close colleague. My heart goes out to his family. As those of us in his pretend one hold on to the memories of our intense and beautiful time together. The love between Tony and Carmela was one of the greatest I've ever known.

Jamie-Lynn Sigler
This news has left me heartbroken. I can only imagine the pain his family feels at this time, and my heart goes out to them, especially Deborah, Michael and Liliana. I spent 10 years of my life studying and admiring one of the most brilliant actors, yes, but more importantly one of the greatest men. Jim had the ability, unbeknownst to him, to make you feel like everything would be alright if he was around. I treasure my memories with him and feel so honored that I was an up close witness to his greatness.

Steven Van Zandt
I have lost a brother and a best friend. The world has lost one of the greatest actors of all time. Maureen and I send our deepest sympathy and love to Deborah, Michael, Lily, and all of Jimmy's family.

Michael Imperioli
Jimmy treated us all like family with a generosity, loyalty and compassion that is rare in this world.. Working with him was a pleasure and a privilege. I will be forever grateful having had a friend the likes of Jimmy.

Lorraine Bracco
We lost a giant today. I am utterly heartbroken.

Steven Schirripa
Jimmy was a dear friend and like a brother to me. He was a great actor and a great father. I will miss him terribly. I am very sad.

Brad Pitt
I admire Jimmy as a ferocious actor, a gentle soul and a genuinely funny man. I am fortunate to have sat across the table from him and am gutted by this loss. I wish his family strength and some semblance of peace.

Bryan Cranston
I'm saddened by James Gandolfini's passing. He was a great talent & I owe him. Quite simply, without Tony Soprano there is no Walter White.

Kevin Bacon
JG ushered in a new age of TV acting and is the reason many of us are there today. His work was inspirational. Hearts out to his people. RIP

Patricia Arquette
James Gandolfini was so talented. It is a loss not just for his colleagues but 4 those who appreciate good work.

Jerry Ferrara
Rip James Gandolfini. One of the greatest actors of our generation.

Lindsay Lohan
James Gandolfini was a dear friend and a great man. My heart goes out to his family. He will be greatly missed

Samuel L. Jackson
Massive blow to the acting community today... The passing of James Gandolfini. So talented. My heart goes out to his family!

Olivia Wilde
James Gandolfini was a kind, funny, wonderful guy. I'm so lucky to have worked with him. Sending love to his family. Such a sad, sad day.

Debra Messing
Heartbreaking news about James Gandolfini... Shocking. HUGE loss. Kind, humble, and a Singular Talent. Rest in Peace.

Susan Sarandon
So sad to lose James Gandolfini. One of the sweetest, funniest, most generous actors I've ever worked with. Sending prayers to his family.

Ewan McGregor
Jesus. The world just lost one of its great actors. James Gandolfini has passed away. Thoughts to his family. Such a talent. I'm saddened.

Michael Chiklis
James Gandolfini. This is a tremendous loss. A brilliant actor and a wonderful man. Our deepest sympathies to his family. Devastating.

Katey Segal
Speechless. James Gandolfini. Really sad... Hug the kids.

Ron Perlman
Sweet journey home, James Gandolfini... The brightest stars burn the fastest....

Steve Carell
James Gandolfini. What a great loss.

Christina Applegate
I am so deeply saddened by the untimely passing of sweet James Gandolfini! My heart is broken for his family!! I'm in shock

Jonah Hill
I'm truly heartbroken to hear that James Gandolfini has passed away. He is one of my all time favorite actors. Tragic loss.

Busy Phillips
So sad to hear about James Gandolfini. He was such an amazing actor and by all accounts a wonderful person. RIP.

Rose McGowan
I am heartbroken about James Gandolfini. He was a gentle giant and great man. I love this picture, I loved him.

Will Arnett
So saddened by news of James Gandolfini's death. What talent. He shall be missed.

Ken Jeong
I had the honor of meeting James Gandolfini recently. A genius actor & great man. My thoughts & prayers go out to his family. Rest in peace.

Patricia Heaton
I'm heartbroken to hear that James Gandolfini died..my prayers go out to his family. #Sopranos

Elijah Wood
a shocking loss. farewell, James Gandolfini

Whoopi Goldberg
R.I.P. James Gandolfini, A truly fine actor, Didn't know him well but what I did know I liked. Condolences to his family from me and mine

Rachael Ray
Too soon to lose such a gifted actor of screen & stage. Great Jersey guy. Missing James Gandolfini this morning & the days to follow.

Gene Simmons
James Gandolfini passed away yesterday. Sad. I knew James and aside from his Sopranos work, was a warm and caring person. He will be missed.

Michael Moore
James Gandolfini, one of the good guys, kind and generous, and an active supporter of documentary filmmakers. R.I.P.

Gina Gershon
James gandolfini. Cool guy. Great actor. Gone too soon. What a loss. Sad. Hope you are going somewhere fun.

Paris Hilton
RIP James Gandolfini. A brilliant actor. Too young to pass. My prayers go out to his family and friends.

Colin Hanks
So sad to hear about James Gandolfini. Hard to express the profoundly deep sense of loss I feel at this moment.

Eric Stonestreet
Rest in peace James Gandolfini. I'm glad I got to meet you and tell you what your performance(s) meant to me as a fan and actor.

Olivia Munn
RIP James Gandolfini. An amazing actor who changed the game and raised the bar. You will be missed.

Justin Timberlake
This James Gandolfini passing is so sad. My heart goes out to his family in this time. RIP #takentoosoon

Lea Michele
Such sad news about James Gandolfini... What an incredible actor... My thoughts are with his family.

Robin Williams
My thoughts and prayers go out to James Gandolfini's family. An extraordinary actor. RIP, Mr. Gandolfini

Debi Mazar
Husband informed me that #JamesGandolfini just passed,In Italy.Im devastated My condolences 2 his family&friends.He passed in his motherland

Giuliana Rancic
Just heard James Gandolfini has died of a heart attack at the age of 51. So incredibly sad

Charisma Carpenter
Just heard about James Gandolfini... I am so sad to learn this news. Condolences to his family and friends. What a talent. : (

Shane West
RIP James Gandolfini .... An amazing actor. Beyond shocked.

Ralph Macchio
RIP James Gandolfini. Terrible news.

Carson Daly
SO SAD! PRAYING FOR HIS FAMILY- wow- Shocked by this news today...

Golden Globes (James won three for his role in "The Sopranos")
James Gandolfini has died in Italy. Rest in Peace to a wonderful man and actor. You'll be missed.

Artie Lange
You will be missed greatly James Gandolfini Maybe best actor ever on a tv series. Salute'

Lance Bass
So so so sad about James Gandolfini - 51 is way too young.

Lucy Hale
So sad to hear about James Gandolfini. RIP

Eric Balfour
RIP James Gandolfini... He was one of my idols, an amazing artist, and his work will be soarly missed!

Vinny Guadagnino
Wow . Gandolfini one of the best ever . TERRIBLE!!!

Marlee Matlin
Shocked at reading about the untimely passing of James Gandolfini. A man of enormous talent. What shocking and sad news.

Josh Henderson
Just read about James Gandolfini.. Never met him but what a damn good actor. Gone way to soon. Rip brother.. #prayers

Josh Groban
Thank you James Gandolfini for some of the most brilliant tv moments of all time. So sad!!!

Damon Lindelof
James Gandolfini. You created an icon. And you cut to black way too abruptly. Thank you, and rest in peace.

Julie Benz
so incredibly sad.... RIP James Gandolfini ... your work inspired and entertained... so incredibly sad.

Russell Simmons
Not tony soprano! Damn. Such a good guy and a great actor. James, rest in peace.

Wes Craven
Farewell to the great American actor James Gandolfini. I was a huge fan. My condolences to his family and his many fans.

Kevin Smith
RIP James Gandolfini! Your iconic portrayal of mob boss Tony Soprano gave soul to a monster and fostered perverse pride in the Garden State!

Melissa Gorga
No... James Gandolfini one of my favorites. RIP. prayers to his family.

Dominic Monaghan
Oh man James gandolfini died. Fantastic in the soprano, and true romance. A great talent.

Pauly D
Wow RIP #JamesGandolfini !!!! My Favorite Show Of All Time The Sopranos , My Heart And Prayers Go Out To Your Loved Ones

Leah Remini
R.I.P James Gandolfini. My prayers to his family and friends. He will certainly be missed by us who loved watching him

Will Sasso
Saddened to hear that James Gandolfini has passed. He was as talented an actor as there ever was. I've met few people with as much presence.

Colton Haynes
So saddened to hear about the passing of one of my favorite actors, James Gandolfini. #RIPJamesGandolfini

Teresa Giudice
So sad to hear about James Gandolfini. My thoughts & prayers are with his wife & kids.

Bethenny Frankel
Just heard TV icon James Gandolfini has died. I'm shocked. I'm sad. I loved his work. My heart goes out to his family.

Rachelle Lefevre
Had the pleasure of seeing the funny, powerful, incredibly talented James Gandolfini on stage in "God of Carnage." He'll be truly missed.

Octavia Spencer
RIP James Gandolfini. So sad!!

John McCain
RIP James Gandolfini, one of the nicest guys I've ever met

Kristin Chenoweth
NO. Not James Gandolfini. He was in my top 5 favorite actors EVER. :(

Brian Baumgartner
I am shattered by the news of the loss of my longtime hero and new friend, James Gandolfini. My thoughts and prayers go out to his family.

Mia Farrow
awful awful news. James Gandolfini will be missed. He was a great actor. Just great.

Gilles Marini
R.I.P James Gandolfini . Was an honor to teach your son Soccer and to have known You. You were such a great man and father. #Heartbroken

Freddy Rodriguez
RIP to my old network mate James Gandolfini

Molly Ringwald
James Gandolfini. You will be missed.

Shannon Elizabeth
Rest in peace James Gandolfini. What a huge loss for Hollywood. I'm deeply saddened & he will be gravely missed. Unbelievable talent.

Rob Thomas
R.I.P. James Gandolfini. Such a great actor. More than just tony soprano and that would have been a lot on its own.

Shannen Doherty
James Gandolfini.. So talented, so nice and far too young to be taken away. You will be missed Sir

Bryan Greenberg
Had the pleasure to work with James Gandolfini twice when I started out. Both times I had small roles but he treated me with respect. RIP

Autumn Reeser
Terrible news about James Gandolfini's passing...I was fortunate to see him in 'God of Carnage' in New York. He was a truly wonderful actor.

Minnie Driver
So incredibly sad to hear about James Gandolfini. He was magic.