Chris Watts Case: Shanann Watts' Brother Details Family Heartache as He Thanks Well-Wishers

Frankie Rzucek shared a heartfelt message of thanks for those who have supported his family.

The brother of murdered Colorado mom Shanann Watts said his family's "whole world was flipped on its head" by the tragedy, as he shared a heartfelt message of thanks for well-wishers.

"I just wanted to take a minute and thank everyone who has helped us in every way possible," Frankie Rzucek wrote in a lengthy Facebook post late Thursday. "From best friends and family to people from all over THE WORLD."

His older sister Shanann, who was 15 weeks pregnant, and her two children, 4-year-old Bella and 3-year-old Celeste, were last seen alive near their Frederick, Colorado, home on Aug. 13.

Their bodies were found days later and it emerged they had been strangled.

Her husband, 33-year-old Chris Watts, is accused of killing them. Investigators said he was having an affair with a co-worker.

Watts told authorities he strangled his wife in a rage after she strangled their daughters, according to an arrest affidavit from Frederick police.

"Never in my wildest dreams would I have ever dreamt such a horrific nightmare and just plain heartbreaking tragedy would ever happen to my regular ol happy family," Rzucek wrote.

Shanann's father, Frank (left), sits with her brother, Frankie, during Chris Watts' arraignment. Frankie has shared a thank-you message for well-wishers. - Pool/Getty Images

"Our whole world was flipped on its head and changed our lives forever. We lost so much in a blink of an eye, but we also gained love and support from people all over and they became part of our FAMILY. I've never felt so loved in all my life, we can't thank you all enough."

He also had some words for his sister, who he called "an inspiration."

"You changed the world without even knowing," he wrote. "I hope we made you proud."

Chris Watts faces three counts of first-degree murder; two counts of first-degree murder for causing the death of a person under the age of 12 while being in a position of trust; one count of unlawful termination of a pregnancy and three counts of tampering with a deceased body.

He has not yet entered a plea. 

Watts has been placed under suicide watch as he awaits trial and is under close watch protocol at Weld County Jail, where he must be checked on every 10 to 15 minutes to ensure his well-being, HLN’s Crime & Justice with Ashleigh Banfield reported.