The pastor at Leisner's church in Minnesota told the Smoking Gun that the 65-year-old died of a heart attack in his car on Saturday "while waiting in his car for two of his children to finish playing tennis."
Leisner's protest, which was aimed at General Mills' support of same-sex marriage, was posted to YouTube on Aug. 5. It shows the man igniting a bowl of Honey Nut Cheerios on the lawn at the corporation's headquarters in Golden Valley, Minn. However, the fire gets out of control, and he is forced to abort the demonstration and flee the scene.
Originally reported by Good as You blogger Jeremy Hooper, the video caused a sensation among the LGBT blogosphere and prompted a criminal investigation by police. Leisner's death brings that investigation to an abrupt end.