The 22-year-old singer was in Miami Beach when she collapsed Monday afternoon, according to A purported eyewitness claims Rita was taken off the beach on a stretcher and wheeled into a waiting ambulance at approximately 2:30p.m. local time. She was apparently just about to start shooting near the the SoHo Beach House hotel when the alleged incident occurred. The website reports the star has been admitted to Mount Sinai Medical Center. A spokesperson for the star has not commented on the claims. Rita was seen smiling while out and about in New York City on Friday. By Sunday she was already in Miami, posting a photo of herself and friend Chris Appleton enjoying drinks in the Florida hotspot.