Reports now say that Fritzl had not only planned that cellar in 1978 but that Elisabeth, 18 when she was locked up and 42 when she was released, was forced to help build the dungeon where she was kept by her sadistic father.
Even though she was 18 years old when she was first drugged and tied up in that cellar, with a dog leash used to keep her from escaping, reports now indicate that Josef had been sexually abusing her since she was just 11 years old.
She did escape once from his home when she was 16 years old, but was dragged back and locked up when her father thought she might attempt to escape his brutality again.
She told police that Mr Fritzl forced her to help drag a 270kg concrete and steel door into position to seal the dungeon. It was only when it was in place that she discovered she had helped to build her own prison.
Mr Fritzl finally agreed to expand the cellar - again with Elisabeth's help - after she had given birth to two of his children.
He forced her to dig out the chambers by hand, working for hours at a time. The process took nearly a decade.
One of the new rooms was used as a punishment area and Mr Fritzl would take his daughter there and rape her.
Reports also say there were 8 doors in the underground dungeon of horrors.
The three children kept downstairs in the cellar with Elisabeth, were Kirstin, now 19, Stefan, 18, and Felix now 5.
The other three children, Lisa, 16, Monika, 14 and Alexander, now 12, lived upstairs.
Kirstin, the 19 year old was brought to the hospital, which led to Elisabeth being released after doctors made public pleas for the mother of the critically ill girl to come forward to provide some medical history.
If not for Kirstin being brought to the hospital, Elisabeth and her children might still be living that nightmare.
Kirstin is better but she is still in an induced coma and doctors have not specified how long they will need to keep her that way.
According to the officer leading the police investigation, Franz Polzer, "She said that there was only one single room at first between 1984 and 1993. The dungeon was expanded as the children were getting born.
"There are still areas we haven't found inside the dungeon and I expect it to take at least two weeks before we have answered all the questions we need to about how Mr Fritzl controlled the areas and imprisoned the children.
"Areas of the dungeon appear to have been under construction and it is possible Mr Fritzl may have been planning to expand it even further."
Fritzl is charged with rape, incest and kidnapping. Prosecutors want to see him charged with murder following the death of his and Elisabeth's three-day-old child 12 years ago and his defense attorneys are going to plead insanity.
More of the sick twisted story at AFP.
Previous:
Austrian man Locks Wife and Children In A Cellar For Years
.