Michael Madsen's manager previously said, 'What we understand is Michael had a cardiac arrest and was found unresponsive in his Malibu home' on July 3. The 'Kill Bill' actor was 67.

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.

Madsen was found unresponsive in his home in Malibu, California, on Thursday morning and pronounced dead, Los Angeles County Sheriff’s Department watch commander Christopher Jauregui said. He is believed to have died of natural causes and Madsen’s manager Ron Smith said cardiac arrest was the apparent cause.