Rob Reiner and his wife, Michele, reportedly tried to help their son Nick before their tragic deaths.

The acclaimed director behind classics like The Princess Bride (1987) and When Harry Met Sally (1989) faced unimaginable personal tragedy when he and his wife were found fatally stabbed at their Brentwood, Los Angeles, home on Sunday, Dec. 14.

Nick Reiner, 32, is a suspect in the deaths.

The Reiners’ story is intertwined with struggles over addiction. In 2016, Rob and Nick collaborated on Being Charlie, a film about a teen battling substance abuse.

The screenplay, co-written by Nick, drew from his own experiences of cycling through more than 18 rehab programs and periods of homelessness.

“It forced us to look at what each other was going through,” Rob said in a PEOPLE interview that year. “Our relationship is better now than it was, and it’s got places to go.”

Michele, a photographer and producer, and Rob, known for his bushy beard and warm demeanor, were devoted parents. Friends and colleagues had long known of the family’s efforts to support Nick through his “dark years.”

Despite years of trying to help their son, the tragedy that struck their home has left Hollywood and fans alike in shock, mourning the loss of a legendary filmmaker and his wife.

RELATED: Michelle Obama had dinner plans with Rob Reiners on night of murders