Kanye West says he is shocked by the news that Chris Brown allegedly assaulted girlfriend Rihanna.
"I was completely devastated by the concept of what I heard," the rapper said Tuesday on Ryan Seacrest's KIIS-FM radio show.
Kayne West - who saw them Saturday at Clive Davis' pre-Grammy party in L.A. -- said he learned the sad details shortly before he performed "American Boy" with Estelle on Sunday's Grammys.
"I was completely devastated during the performance," West said.
He said he knows Rihanna better than Brown, 19, as he went on tour with the 20-year-old singer.
"Rihanna is so important to our culture ... to pop music," said West. "I feel like she is the most important artist in music and has the most potential. Her taste level and her age ... she has the potential to be the greatest artist of all time.
"In that sense, I feel like that's my baby sis," he said of Rihanna. "I would do any and everything to help her in any situation.
Although West didn't want to get into specifics, he said, "All I want to say is, it's so devastating. Just as a person, I don't care how famous she is or even if she just worked at McDonald's ... [abuse] should never happen. It should never come to that place."
Actor Terrence Howard tells Hollywood.tv that "everybody needs to get out of [Rihanna and Chris Brown's] way."
"Chris is a great guy. He'll be all right," Howard says. "And Rihanna knows he loves her."
"The Insider" confirmed that Rihanna would not be performing at the Grammys after sources say she sustained a bruised face in what was called a car accident.
Chris is Rihanna's rumored boyfriend and is under investigation for allegedly making "criminal threats" to a woman he'd been riding with in a car who sustained what police called "visible injuries."
While some reports claim the woman was Rihanna, police have yet to identify the accuser.