Margot Kidder Said She Was Fighting the Flu Days Before Death

"Superman" star Margot Kidder was battling the flu just 4 days before she died, and talked about her struggle during what appears to be her final interview.

Kidder phoned in to “The Drew and Mike Show” in Detroit on May 9 to promote an upcoming appearance at Motor City Comic Con. She told the hosts she was "in bed with flu" because she's "puking every hour and a half." Kidder sounded rough, very raspy -- and, even though she was in good spirits, she said the flu battle was "not fun."

As we previously reported ... Margot was found dead Sunday at her home in Livingston, Montana. Cops responded to a call that Margot was unconscious and not breathing. Her death is under investigation, but police have said they don't suspect foul play.

Kidder was 69.