Mariah, who worked with Whitney on the song "When You Believe" from the animated The Prince Of Egypt, expressed her sadness on Twitter.

"It's 2/11..remembering my friend the incredible Whitney Houston. It's been a year & still so hard to believe. Her legend lives on eternally"

Last year, Mariah said her song "Triumphant (Get 'Em)" was inspired by Whitney and helped her move on when she thought it would be nearly impossible.

Jordin, who played Whitney's daughter in the singer's final film, Sparkle, tweeted a photo of a rosary with the engraving "2-11-12" made in honor of the diva.