Veteran stage and screen actor Gene Janson was starring in Gore Vidal’s The Best Man at Chicago’s Victory Gardens Greenhouse Theater.  He played a fictional U.S. President; his character dies halfway through the play.

Janson didn’t make it that far:

Mr. Janson was 20 minutes into the show… when he put his head in his hands. When asked if he was OK, he replied no. He was rushed to Lincoln Park Hospital and died soon afterward, with members of his family surrounding him. He had suffered a heart attack.

More from Playbill.

Call it the Irene Ryan syndrome. (Irene Ryan, better known as "Granny" from The Beverly Hillbillies suffered a stroke during a Broadway performance of "Pippin" and died several days later).