Posting a fun behind-the-scenes photo from the set of "Batman," star Adam West has expressed his sorrow at the passing of co-star Yvonne Craig.

"I was deeply saddened for us to lose Yvonne," West said in his Facebook post. "It was too soon. She always brought humor and a fine attitude to our stage. She was a joy to work with. A good person. My heartfelt condolences to Yvonne's family. We will miss her."

Yvonne Craig, TV's '60s Batgirl, Dead at 78

Craig, best known for her role as Barbara Gordon/Batgirl on the third season of the 1960s "Batman" TV series, passed away earlier this week at age 78.

I was deeply saddened for us to lose Yvonne. It was too soon. She always brought humor and a fine attitude to our stage....Posted by Adam West onWednesday, August 19, 2015