The 43-year-old Scottish actor told People that when he heard the news of the tragic car crash it "just broke my heart." Butler added that the Fast & Furious star was "one of the nicest people I've met."
That very impression about Walker's character seems to be a sentiment shared by many.
Butler and Walker appeared in the science-fiction thriller Timeline in 2003.
The mag caught up with Butler on Wednesday, Dec. 4, at Art Basel in Miami.
Walker, and the driver of the vehicle, Roger Rodas, passed away on Saturday, Nov. 30.
After attending a Reach Out WorldWide charity event, Rodas and Walker went for a drive in a Porsche Carrera GT and never came back. Their vehicle struck a light pole, two trees and a speed limit sign. When police arrived on the scene in Santa Clarita, Calif., deputies found the vehicle engulfed in flames. Both men were pronounced dead at the scene.
The Los Angeles County coroner's office confirmed that Rodas, 38, died of multiple traumatic injuries, and Walker, 40, died of the combined effects of traumatic and thermal injuries.
The deaths were ruled to be accidental. Toxicology results are pending and may take several weeks.