Max Shacknai died at Rady's Children's Hospital in San Diego yesterday, one week after the fall, Medicis Pharmaceuticals chairman and chief executive Jonah Shacknai said.
On Monday, Max fell down the stairs at the Spreckels mansion in Coronado in what police called a tragic accident. He was not breathing and did not have a pulse when paramedics found him.
© The Associated PressTragedy: Six-year-old Max Shacknai died one week after he fell down the stairs of his millionaire father's mansion
On Wednesday, officials said Mr Shacknai's 32-year-old girlfriend, Rebecca Nalepa, was found dead hanging nude from a balcony at the mansion, her hands and feet bound.
Mr Shacknai's brother, Adam, who was staying in the mansion guesthouse, called to report Nalepa appeared to be dead, police said. Jonah Shacknai was not at home.
Sheriff's Captain Tim Curran has called the death 'very bizarre.'
© watodayTogether: Jonah Shacknai with his 32-year-old girlfriend Rebecca Nalepa, who was found dead hanging nude from a balcony at his mansion
Victim: Rebecca Nalepa, 32, pictured on the left with her son, was found wrapped in cord after apparently hanging at the millionaire's mansion
Sheriff's investigators have not established any connection between the two deaths, and have not determined if Ms Nalepa was a crime victim and have made no arrests. They said they have not ruled out suicide.
In joint a statement with ex-wife Dina Romano, the boy's mother, Mr Shacknai said: 'With great sadness, Dina and I convey the tragic passing of our beloved son, Max (affectionately known as Maxie).
'Despite heroic efforts on the part of paramedics and hospital staff, he was unable to recover from the injuries suffered early last week. His loving, kind and vibrant spirit will be forever in our hearts and those whom he touched every day.'
Ms Nalepa n was discovered naked, hanging from a second-storey balcony with her feet and hands bound with orange electrical cord, police have revealed.
Ms Naelpa met what officers described as a 'very violent and very suspicious end' at the mansion.
While an autopsy has been completed, police are not releasing the details and have not yet ruled whether her grisly death was murder or suicide.
© NBCSprawling: The mansion where Nalepa's body was found, which is owned by pharmaceutical millionaire Jonah Shacknai
Speculation mounted it could be connected to the accident just days before, when Mr Shacknai's son fell down the property's grand staircase.
Miss Nalepa, a Burmese woman who had been in a relationship with Mr Shacknai for two years, was reportedly looking after the little boy at the time.
The mystery surrounding her death, which police have described as 'bizarre', deepened as it emerged a loud party had been held at the 27-room house on Tuesday night, the day before Miss Nalepa died - and the day after the little boy's accident.
San Diego County Sheriff's Office said Miss Nalepa's naked body was discovered by Mr Shacknai's brother, Adam, early on Wednesday morning.
Multi-Millionaire: Jonah Shacknai is the founder, chairman and CEO of the Medicis Pharmaceutical Corporation
He cut her down from the balcony to try to save her, before calling 911.
Firefighters tried to revive Miss Nalepa, who they described as being 'in distress', but she was later pronounced dead at the scene.
When news cameras circled overhead, her naked body was lying sprawled in a grassy courtyard, with what appeared to be orange electrical wire trailing to one side.
Tim Curran, with the San Diego County Sheriff's Department, described the circumstances as 'very suspicious', telling NBC San Diego that it appeared the victim had died a 'violent' death.
He refused to rule out suicide, saying: 'That is a possibility. [The] circumstances are bizarre.'
'It appears to be some type of a violent death, and I'm not going to compromise the integrity of the investigation by giving anything more than that at this time,' he added.
Mr Curran said Adam Shacknai is not currently being considered a suspect, although he was the only other person believed to have been in the 27-room mansion when Miss Nalepa died.
Both brothers and Mr Shacknai's ex-wife Dina, who is six-year-old Max's mother, are being questioned by police as witnesses, Curran said.
Discovery: Rebecca, left was found hanging from a balcony naked by her boyfriend's brother Adam, right
© CBS 8Violent end: Sheriff's deputies described Rebecca Nalepa's death as "very suspicious and violent"
Crime scene: The cordoned off $17m Spreckels Mansion, on San Diego's exclusive Ocean Boulevard
In May, Miss Nalepa, who had lived with Mr Shacknai for about two years, had successfully petitioned to revert to her maiden name, Rebecca Zahau.
Her ex-husband, Neil, told 10News; 'This is all overwhelming. I'm just trying to wrap my head around it.
A friend told NBC San Diego Miss Nalepa was a 'survivor' who would never have allowed herself to have been seen naked and would not have considered suicide.
Nalepa's brother-in-law Doug Loehner also issued a statement, defending her boyfriend.
'Jonah is a stand-up guy. He was very devoted to Rebecca. She treated his kids as her own,' he said.
The 27-room Spreckels mansion was built in 1908 in the wealthy seaside suburb of about 24,000 people on San Diego Bay. It is named for its original owner John D. Spreckels, who also owned the majestic Hotel del Coronado and two local newspapers, the San Diego Union and San Diego Tribune.
Coronado had just one homicide last year, and the police department asked the sheriff's department to help with the investigation.
Jonah Shacknai, 54, founded Medicis, based in Scottsdale, Arizona, and has been chairman and CEO since 1988.
The company's products include acne treatments Solodyn and Ziana and facial wrinkle treatment Restylane.
Suicide?? With hands and feet bound? Yeah, right.