Why did Lars Hanson leave Little House on the Prairie?

Lars Hanson appeared in many of the first seasons of Little House on the Prairie as a recurring character in Walnut Grove, as the town’s founder and owner of the local Mill.

Karl Swenson, who portrayed Lars Hanson on the show, asked to be written out of the show, and at the end of his final episode, Melissa Gilbert did a voice-over as Laura Ingalls saying that Lars Hanson had passed away.

In an unfortunate twist of events, shortly after he filmed that final episode, he died of a heart attack in real life. The episode ended up airing 8 days after Swenson passed away.  Many have speculated he knew he was becoming ill and that is why he asked Michael Landon to write him out of the show.