Mariah Carey struggles to sing 'All I Want For Christmas Is You' live (VIDEO)

Mariah Carey struggled to sing 'All I Want For Christmas Is You' live on Christmas in Rockefeller Center on Wednesday, December 3, 2014.

OMG she struggled! What a disaster. I felt so bad watching her.

Mariah has lost it. She's still trying to please her fans which is commendable but the voice is not there anymore. Those runs... ran away from her!

MORE: Watch Mariah's Isolated Vocal Track

TMZ reported that Mariah was LATE for the taping of the special in New York City this week and NBC canceled her appearance. However, she opted to sing LIVE tonight during the tree lighting to not disappoint her fans.

Well I'm disappointed. The old Mariah who can sing notes flawlessly is never going to appear again. Even more evidence tonight.

My god I'm having such a hard time being festive after watching this.

Watch the video here:

Mariah Carey struggles to sing 'All I Want For Christmas Is You' live