The CBS cast paid tribute to Williams after learning of his unexpected passing in a motorbike accident on Monday, saying, “I will miss him but I will not forget him.”

Blue Bloods’ cast is paying tribute to late co-star Treat Williams, who passed away in a motorbike accident on Monday at 71.

Williams has a close friendship with Tom Selleck, who plays New York City police commissioner Frank Reagan in the enduring CBS crime thriller.

Selleck, 78, said, “It has been said that we are all only passing the time and occupy our chair very briefly. My friend Treat was perfectly seated in his chair and had an excellent name. I will miss him but I will not forget him.”

Williams was praised by Bridget Moynahan, who plays Erin Reagan on the show, as an “actor’s actor” and an “absolute pleasure” to work with.

According to Moynahan, 52, “He was a role model off-screen as well.” “Everyone could admire his love and commitment to his family. Folks, we lost a good one.”

Eddie Janko-Reagan’s on-screen wife, Vanessa Ray, expressed her admiration for Williams by posting a story about him on Instagram.

“Treat found out I was in Hair on Broadway at family dinner the first time I worked with him on @bluebloods_cbs,” Ray wrote. “I introduced myself as the ‘Frank Mills’ girl. He started singing. He knew every word. I didn’t. What a brilliant, kind, and lovely artist. Rest now sweet Berger.”

Prior to his death, Williams — who played the recurring role of Lenny Ross on Blue Bloods — shared several photos from the show’s set on social media over the years.

One memorable post came in August 2021 when he shared a photo with Selleck on the set of the CBS drama. “Thanks Tom Selleck and #Bluebloods always a pleasure. Two old pros,” he captioned the image.

Williams’ agent of 15 years, Barry McPherson, confirmed his death to PEOPLE on Monday, describing the “talented” actor as “the nicest guy.”

“He was an actor’s actor,” McPherson said. “Filmmakers loved him. He’s been the heart of Hollywood since the late 1970s.”

Williams was driving his motorcycle near his Vermont home on Monday when he was struck by a car on Route 30 near Dorset, Vermont, Fire Chief Jacob Gribble told PEOPLE. Per Gribble, investigators believed the driver of a car was turning and didn’t see Williams’ motorcycle before the two collided.

The actor sustained “critical injuries” and was airlifted to a hospital in Albany, New York, where he was pronounced dead. Police have since confirmed the investigation is ongoing.

In addition to the Blue Bloods cast, many of Williams’ friends and costars have honored the actor on social media following the news of his death, including Gregory Smith, Laura Dern, Marilu Henner, Jonathan Bennett, Sarah Drew, Melissa Gilbert, Wendell Pierce and Kim Cattrall.