Yolanda Foster
"The Real Housewives of Beverly Hills" stars react to the news that Yolanda Foster, photographed on the red carpet ahead of the Victoria's Secret fashion show at the Lexington Avenue Armory in New York City on Nov. 10, 2015, is divorcing David Foster. Getty Images

On Tuesday, the same night Bravo's "The Real Housewives of Beverly Hills" returned for it's sixth Season, Yolanda and David Foster announced that they would be separating. The couple was married for four years and together for nine before deciding to divorce. Now the reality star's castmates are speaking out about the shocking news, which most of them say they never saw coming.

As was reported by E! Online, Kyle Richards appeared on Bravo's "Watch What Happens Live" after the "RHOBH" Season 6 premiere. During her visit she was asked by host Andy Cohen to share her thoughts on Yolanda's divorce. Kylie, 46, said she was shocked by the news but admitted there were some signs of trouble in paradise. She went on to suggest that some of their issues may have been a direct result of the 51-year-old former model's battle with Lyme disease, though she couldn't confirm that was the cause. Kyle told Cohen, 47, she felt "really bad" that Yolanda was going to have to battle her ailment, which seemingly continues to get worse and worse, and a divorce.

"I mean, we didn't know. I think that they've been struggling and Yolanda's been so sick. I don't know if that has anything to do with it. It's so sad," Kyle said.

Yolanda's fellow cast members and former co-stars have taken to social media to express their feelings on the split. Adrienne Maloof, who left "RHOBH" several seasons ago, sent "positivity and love" to Yolanda on Twitter. Franchise newcomer Eileen Davidson sent her love and apologies to both Yolanda and David, 66.

News of their split broke Tuesday evening. The couple released a joint statement to E! News in which they expressed their love for one another while revealing that they had "decided to go our separate ways." Yolanda and David told E! that they were "grateful" for the many happy years they'd had and claimed they "did our best" to work things out. They also expressed the hope that they would be able to move forward with "love and respect" for one another.