Michael Madsen, a frequent Quentin Tarantino collaborator on films like "Reservoir Dogs" and a veteran actor in "Free Willy" and more, has died at 67.

Michael Madsen, a tough guy character actor and frequent Quentin Tarantino collaborator, has died at the age of 67.

Michael Madsen, a prolific character actor best known for his frequent appearances in Quentin Tarantino films, died Thursday morning. The cause of death, his manager said (per NBC News), was cardiac arrest. He was 67.