"My head is still screaming for you," wrote Ruth Gibbins of her late brother.
The former contestant's sister shared the news on Facebook.
The iconic singer-songwriter died at 78 years old Thursday (Jan. 30).
The band shared a joint statement one day after the star died in Buenos Aires, Argentina.
The late star attended St Peter's Collegiate Academy before finding fame on X Factor.
The news has also ignited an outpouring of shocked messages from fans.
Tommy died one day after the 21st anniversary of his older brother's passing.
No further details about the nature of Patricia and Alison's deaths have been made public.
The businessman propelled the careers of Reykon and Blessd, to name a few.
The Grammy-winning American Idol finalist was 47 years old when she was found dead on April 18.
