Florida billionaires Jackie and David Siegel experienced a parents' worst nightmare when their reality TV mega-mansion dream turned into a death sentence for their fragile teen daughter.

Victoria Siegel, nicknamed "Rikki," passed away on June 6, 2015, after a long and rocky battle with addiction and depression possibly stemming from her time on her family's documentary, The Queen of Versailles. She was just 18 at the time, and there is not a day that goes by that her heartbroken parents don't wish they could've seen the signs.

Jackie says Victoria was a happy girl up until she turned 15 and the family got involved in The Queen of Versailles. She began to suffer from anxiety and to be bullied in school about her weight and her wealthy family's lifestyle.

"That was kind of the beginning of the end for Victoria. That movie embarrassed her, she was kind of on the chubby side at the time," says David in the interview.

He added that the teen started going on crash diets to slim down.

"The bullying was very difficult for her and I have a feeling that's why she started experimenting with drugs," says Jackie.

Looking back, Jackie says there were many red flags in Victoria's behavior. Towards the end of her life, she constantly made excuses to lock herself in her room, claiming she was tired and needed to nap.

At a young age, Victoria became addicted to antidepressants. Though she was prescribed Xanax for her anxiety and depression, she began exceeding her doses and relying on the pills. Eventually, she began experimenting with other drugs such as marijuana, cocaine and Adderall — a habit her parents noticed when it was too late.