Why Did My Father Die Of Heart Failure In Kaiser's Care?

Why did my father die of heart failure in Kaiser's care? My father suffered a major heart attack two weeks ago. He went to the main hospital (not Kaiser) where they performed an Angioplasty surgery on him. When I went in to see him, he looked great. Nice coloring of the skin , seemed like normal. The doctor said he looked great for what he went through. He was in the ICU where they took the balloon out (I don t know why it comes out?) and they have a DVD of his surgery where the doctor says he was waiting for him to have another heart attack. WHY, if he was in such bad condition, did Kaiser not put him in the ICU when he was moved to Kaiser from the other hospital. He died because nobody was watching him in a regular hospital room. They were going to send him home the day he died because they said he was fine. I called my mom and she said he was doing really good and no longer in the hospital bed, but sitting up in a chair. THAT very day, he died suddenly from a heart attack in the hospital and a nurse found him in the bathroom?