He was born with the name John Joseph Edward Cassidy, but in Hollywood, he was Jack.
He was known as a brilliant character actor often playing the suave, sophisticated ladies man/heartless brilliant killer in shows like "Columbo". He married Actress/Entertainer Shirley Jones but he had a son with his previous wife naming him David. With Shirley they had three sons: Shaun, Patrick and Ryan. (an interesting note: Shirley was pregnant with Patrick during filming of "The Music Man". During one scene in which Robert Preston had to kiss her, the baby gave a good kick! "What was that", asked a startled Robert Preston? With a smile, she said, "That was Patrick Cassidy."
Years later, Patrick got to meet Robert Preston and introduced himself. Robert Preston shook his hands and with a smile, he said, "I know. We've met.")
Jack and Shirley got divorced in 1974.
Two years later, after coming home to his 4rth floor West Hollywood Apartment from a party, he lit a fire in the fireplace, had a few drinks and then went to lay down for a smoke on the sofa.
He fell asleep.
The worst thing that could happen happened.
The sofa caught fire and before long the entire apartment was engulfed in flames, as was Jack.
He tried in vain to get out of the apartment but died in the fire. He was identified by his ring which bore the Cassidy Family crest. What remained of him was cremated and scattered at sea. Even though the body of Jack Cassidy was gone, it has been said that he liked his apartment so much that he never left. The current residents had a guest sleeping in the guest room who awoke one morning to find Jack's ghost standing in the doorway, leaning against the jam. He had evidently been watching the guest sleep. As soon as Jack realized he had been seen, he slowly faded away. The owners found a way to appease Jack's ghost by putting a portrait of him behind the bar. The previous owners had moved out because they had also encountered Jack's ghost. Jack's ghost is obviously still there. When Scott Michaels went by to do some filming there for his documentary "Dearly Departed", the fire house in the 4rth floor hall moved by itself.