OLIVE TOWNSHIP, Mich. (WOOD) — The former Grand Haven schools administrator who was accused of embezzling from the district died of cardiovascular disease, his death certificate shows.

Brian Wheeler, 56, died at the Ottawa County Jail in West Olive on Jan. 27. The sheriff’s office said deputies found him unresponsive around 8 p.m. and efforts to resuscitate him failed.

Wheeler’s death certificate says he died of atherosclerotic and hypertensive cardiovascular disease. The cause of death was listed as natural.

Athersclerosis is a hardening of the arteries caused by plaque buildup. Hypertensive heart disease is caused by high blood pressure. The death certificate indicated Wheeler had the cardiovascular problems for years before his death.

The week of his death, Wheeler pleaded no contest to embezzling $100,000 or more and using a computer to commit a crime. Since 2014, authorities said, he had stolen more than $900,000 from Grand Haven Area Public Schools, where he was an assistant superintendent. He was fired from the district and arrested in November.