Madsen died from cardiac arrest, his manager Ron Smith told NBC News. Cardiac arrest occurs when the heart stops functioning. It can lead to death without immediate treatment, according to Mayo Clinic.

Actor Michael Madsen got sober before his death last week, though the 67-year-old star’s condition at the time of his death isn’t known.

Virginia Madsen mourned the loss of her brother Michael Madsen with a touching tribute, describing him as "thunder and velvet."