The eldest son of former Republican Arizona Gov. Jan Brewer unexpectedly died over the weekend, the family announced on Monday.

“Heartbreaking news for me,” Brewer wrote on Twitter, announcing the death of Ronald Brewer, 54. “Prayers for me and my family as we grieve are greatly appreciated.”

The exact cause of the son’s death wasn’t clear. The obituary shared by Brewer noted that he died in his sleep on Saturday and emphasized his “adventurous spirit and outgoing personality’ and “beaming smile, sense of humor and giggle.”

“He attended private high school in Provo, Utah and graduated valedictorian of his class,” the obituary read. “Ron loved his shoes, which would take him to his favorite activities like camping, enjoying nature, picking out flowers and experiencing hiking up the Hole in the Rock to watch the brilliant Phoenix sunsets. He'd share anything he had with anyone he met.”

"Ron loved his shoes, which would take him to his favorite activities like camping, enjoying nature, picking out flowers and experiencing hiking up the Hole in the Rock to watch the brilliant Phoenix sunsets. He'd share anything he had with anyone he met." — Ronald Brewer's obituary

According to the Arizona Republic, the son has been battling mental illness for decades and had to stay much of life in a mental-health facility after he was found not guilty by reason of insanity in a sexual-assault case in 1989.

The former governor said in 2010 that the son “fought hard for his well-being, before and after (the) incident.” His illness, she said, helped to better understand the issues of mental health and informed her policy decisions.

He is the second son Brewer lost. One of her three sons, John Brewer, died in 2007 due to cancer.

Multiple lawmakers, community leaders sent their condolences on social media to the family and the former governor.