MINNEAPOLIS (CBSDFW.COM/AP) – Minnesota Vikings offensive line coach and former Dallas Cowboys assistant coach Tony Sparano died of heart disease.

The Hennepin County medical examiner’s office said on Monday that the 56-year-old coach died of arteriosclerotic heart disease, or hardening of the arteries. The manner of death is listed as natural.

Sparano died Sunday in Eden Prairie, a Minneapolis suburb. He had been Minnesota’s offensive line coach since 2016.

Sparano began his NFL coaching career in 1999 and had stints as head coach with both the Miami Dolphins and Oakland Raiders. Sparano was Miami’s head coach from 2008 through 2011 and went 29-32. He went 11-5 and won the AFC East in his first season with the Dolphins.

Sparano was hired by the Cowboys in 2003 and spent five seasons with the team, rising from tight ends coach to assistant head coach.

Sparano also spent time with the Browns, Redskins, Jaguars and 49ers. He is survived by his wife, two sons, daughter and four grandchildren.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)