LATEST: The ex-boyfriend of Anna Nicole Smith tried desperately to save her from substance abuse hell months before she died of a suspected drug overdose last week (08FEB07). Photographer LARRY BIRKHEAD, who is currently fighting for custody of the former model's daughter DANNIELYNN, insists he spotted danger signs early in their relationship and begged Smith to enter rehab with her son DANIEL, who died from an overdose in November (06). But rather than taking his advice, Birkhead claims his concern tore the couple apart and they split last summer (06). He tells the New York Daily News, "I am sorry that I couldn't save them, I tried. I watched over her to make sure she was safe, and once I was basically pushed to the side ... I had no control over what she did or anyone else around her did." Birkhead insists he was so frightened he studied for Red Cross certificate in CPR in case "there was an emergency". He adds, "I can't help but thinking: Could I have saved Anna if I was with her? Or even Daniel? It keeps playing out in my head." Smith died on her way to hospital on Thursday (08FEB07) after her nurse found her unconscious in her suite at the Seminole Hard Rock Hotel + Casino in Hollywood, Florida.