Actor Gary Graham died of a sudden cardiac arrest at the age of 73 on Monday, the New York Post reported. The "Alien Nation" and "Star Trek" star leaves behind his wife of 25 years, Becky, and daughter, Haylee, from a previous marriage. 

The family is baffled by Graham's sudden cardiac arrest that happened at a Spokane, Washington, hospital, according to Fox News. Although he had a history of heart problems, Becky Graham was blindsided by the rapid turn in his health.

"I always say he was my knight in shining armor, and I was his port in the storm. He was loved by so many," Becky Graham said.

Gary Graham's ex-wife, Susan Lavelle, also shared a fond tribute to him on behalf of herself and their daughter. "It is with deep profound sadness to say that Gary Graham, my ex husband, amazing actor and father of our beautiful only child together, Haylee Graham, has passed away today," Lavelle said.

"We are completely devastated especially our daughter. . . His wife, Becky was by his side," she added.

"I met Gary when I was just 20 years old and he was one half of the star duo on the tv series, ‘Alien Nation.' But he had already been in movies like ‘All the Right Moves’ with Tom Cruise. Of course, Gary has many more credits," Lavelle said.

"Gary was funny, sarcastic sense of humor but kind, fought for what he believed in, a devout Christian and was so proud of his daughter, Haylee. This was sudden so please pray for our daughter as she navigates through this thing called grief," her post continued.

"Fly high into the heavens Gar! Thank you for our journey and thank you for the gifts you left me in acting, my love of horses and most importantly, our daughter," Lavelle concluded.

In a career spanning more than four decades, Gary Graham had several unique roles to his name. The Long Beach, California, native began his career with television appearances in the 1970s on some of the decade's most popular shows.

Gary Graham had roles on "Starsky and Hutch," "The Incredible Hulk," "Eight is Enough" and "Police Woman." He also picked up film roles in "The Last Warrior," "The Spy Within," "The Arrogant," "Steel" and "Robot Jox."

However, his most iconic roles were spread over years in separate science-fiction franchises. Gary Graham played Detective Matthew Sikes in the 1989 television series "Alien Nation," which was based on a hit movie of the same name that starred Mandy Patinkin and James Caan.

Although that series was canceled, Gary Graham went on to reprise his character in several made-for-television movies. The actor also popped up in the "Star Trek" franchise in a few different roles.

Gary Graham appeared as Tanis in "Star Trek: Voyager," the television series, as First Officer Ragnar in "Star Trek: Of Gods and Men" web series, and "Star Trek: Renegades," the film.  He played Ambassador Soval for "Star Trek: Enterprise" from 2001 to 2005.

It's tragic that Gary Graham passed away in such a short period of time. His fans and family didn't have a sufficient window of time to say goodbye or pay tribute before his death.