Lady Gaga, Madonna, Sarah Jessica Parker Remember Alexander McQueen

Emma Roberts, Ashton Kutcher comment on designer's death on 'Valentine's Day' red carpet.

A dark cloud hovers over New York Fashion Week as fashionistas mourn Thursday's death of designer Alexander McQueen (born Lee McQueen), and all over the world, his celebrity friends and fans are expressing sadness over his loss.

Lady Gaga — who premiered "Bad Romance" at McQueen's Paris runway show last fall and later wore his designs in the song's videotweeted a photo of herself and the designer as a tribute to her friend.

"Project Runway" star Christian Siriano, who once worked for the designer, released a statement to MTV News saying, "McQueen has inspired me in every way imaginable in my career. I did not know Lee well, but I feel so grateful for my time spent there. It was an honor to work for him and watch him create and develop his craft over the years. I believe him to be one of the most talented artists of my lifetime."

Madonna also wore many McQueen designs throughout her career. "Lee McQueen was a truly unique visionary in the world of fashion," she said in a statement, according to E! Online. "A creator of beauty. What a tragedy."

On the red carpet for the London premiere of "Valentine's Day" on Thursday, the movie's stars also remembered the legendary designer. "He is actually one of my favorite designers; I love him," Emma Roberts said. "It's really sad. I didn't even believe it when I heard it. I hope his family is doing OK."

"It's a huge loss for the fashion industry," Ashton Kutcher added. "He was a brilliant visionary. My heart goes out to his friends and colleagues."

Pop stars, actors and fashion icons continued to share their thoughts about the designer online and in the press. "Today we lost a true genius, Alexander McQueen," Janet Jackson tweeted. "He possessed a unique creativity that will never be recaptured. Alexander invited me to my very 1st fashion show (his in London). There will NEVER be another!"

"Sex and the City" star Sarah Jessica Parker released a lengthy statement remembering the designer. "He was talented well beyond his years, and the seriousness and unrivaled talent which he applied to his work is in bountiful display year after year and collection after collection," she said. "There has never been anyone like him. And there simply never will be. It has been a privilege for all of us to know you. You will be indescribably missed."

Supermodels are also paying their respects to the late, great designer. Kate Moss' rep said in a statement, "Kate is shocked and devastated at the tragic loss of her dear friend Lee McQueen. Her thoughts are with his family at this sad time. We would also ask that Kate's privacy is respected."

"I am truly devastated to lose my close friend," Naomi Campbell said in a statement. "His talent had no boundaries and he was an inspiration to everyone who worked with him and knew him. This is a sad day to all who loved him around the world, and my condolences are with his family. I will miss him so much; he will never be forgotten."