Rivers and her daughter were discussing their reality show Tuesday on NBC's "Today" show when she complained about her living arrangements, saying, "Those women in the basement in Cleveland had more space."
A Wednesday statement from attorneys for Amanda Berry and Gina DeJesus calls Rivers' remark hurtful and shocking. The attorneys say the women have endured painful media attention and the comment is "a new low" that warrants an apology.
Rivers' publicist hasn't responded to messages seeking comment.
Berry, DeJesus and a third woman, Michelle Knight, escaped last year. Their kidnapper, Ariel Castro, hanged himself in prison.