Kris Allen has been forced to cancel a scheduled appearance due to a death in his family.

The American Idol eighth-season champ has canceled a Wednesday appearance on The Tonight Show with Conan O'Brien due to the passing of his grandmother, a representative for the singer told Access Hollywood in a Tuesday report.

"I know I was supposed to do conan on wed, but there was a death in my family," Allen wrote in a Twitter meesage posted late Monday night.

Allen's fellow eighth-season finalist Allison Iraheta will take his place on the NBC late show.

"Everyone watch [Iraheta] on Wed. She is filling in," Allen wrote in a follow-up message.  "And by filling in I mean [Iraheta] is gonna rock Conan's face off on Wednesday."

Iraheta subsequently used her own Twitter account to offer support for Allen.

"Love ya man .. Keep yo head up," wrote Iraheta, who was joined by former Idol finalist Anoop Desai in offering support.

"I know Kris appreciates all the concern-- keep his family in your thoughts," Desai wrote.

Allen acknowledged comments Tuesday morning.

"Thanks everyone for the love," he wrote.

Allen is not expected to miss any dates on the current American Idols Live concert tour due to his grandmother's death, the rep told Access Hollywood