Priscilla Presley's family is struggling to cope with the death of her grandson, Benjamin Keough.

The actress, who was married to Elvis Presley, wrote on Facebook Wednesday that "the shock of losing Ben has been devastating," and added, "These are some of the darkest days of my family's life."

Keough, the son of Presley's daughter, Lisa Marie Presley, died on July 12 at age 27. The Los Angeles County Medical Examiner-Coroner's Office confirmed last week that he died by suicide.

"Trying to put all the pieces together of all the possible whys has penetrated my soul," Presley wrote in her post. "Each day I wake up I pray it will get better."

Keough was a relatively private individual, though he did appear in the 2005 documentary "Elvis by the Presleys" and in the music video of his mother's 2012 duet with his late grandfather, "I Love You Because."

He is survived by his grandmother, mother and father, musician Danny Keough, as well as his sister, 31-year-old actress Riley Keough, and his 11-year-old twin siblings, Harper and Finley Lockwood.

"I think of my daughter and the pain she is going through as she was a doting mother. Ben’s father, Danny, who is completely lost, as Ben was his only son," Priscilla Presley reflected. "Riley, so loving and so close to him; Harper and Finley, who absolutely adored Ben. [Keough's uncle] Navarone [Garibaldi], who struggles deeply with loss and death. Rest In Peace Ben, you were loved."

If you or someone you know is in crisis, call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255) or contact the Crisis Text Line by texting HOME to 741741.