A New York City snowstorm can’t deter Hollywood’s brightest stars from supporting Natasha Richardson’s favorite charity.

Lady Gaga, Meryl Streep and Sigourney Weaver attended Wednesday’s amfAR gala to raise money to fight HIV/AIDS and honor Richardson, who died in a skiing accident last March.

Richardson became a champion for HIV/AIDS research after her father, director Tony Richardson, died of it in 1991.

Brooke Shields was overcome with emotion on the red carpet and struggled to articulate her feelings for her friend, whom she described as a beautiful woman and brilliant mother.

Streep sang an a cappella Irish number. Lady Gaga performed “Future Love” while covered in pearls and white body paint.

Meryl Streep: ‘it really takes guts to get up and sing after Lady Gaga and Rufus. The sacred and the profane.’ Streep singing an Irish song ‘for Tasha and for all the people who aren’t here tonight’.

More Vanessa Redgrave paying tribute to Natasha: “My darling Natasha, I’m so proud of your courage, your hard work, your total commitment and your beautiful, life-giving spirit. Thank you.”

Richardson’s mother, actress Vanessa Redgrave, described Richardson’s advocacy as her life’s mission.