Update: WHYY will move primetime programming scheduled to air between 8 p.m. and 11 p.m. to Y2 on Tuesday and Wednesday due to Senate coverage, a network spokesperson said.

After more than 13,000 interviews and 40 years on the air at WHYY, Fresh Air host Terry Gross is among the most recognizable figures in American radio. But back in 1973, she was a soon-to-be-fired English teacher at a public school in Buffalo, N.Y.

“I was literally fired in six weeks,” Gross says in an forthcoming appearance on PBS’s Finding Your Roots with Henry Louis Gates, Jr. “For not being able to keep control of the class, or even keep them in the class.”

Gross recounts her experience as part of an episode set to air Tuesday at 8 p.m. on PBS. The show, which details its guests’ histories, is in the midst of its sixth season. Gross’ episode will also feature segments with comedian Marc Maron (who interviewed Gross back in 2015), and actor Jeff Goldblum.

The Fresh Air host has previously discussed her firing from Genesee Humboldt Junior High. In a profile from the State University of New York at Buffalo, from which Gross graduated in 1972 with a bachelor’s degree in English (and later a Master of Education in communications), she said she was “astonished by how swiftly I had failed at my profession.”

By 1975, however, Gross had began her career at WHYY in Philly as host of Fresh Air. The program went national about a decade later, and now reaches about 6 million listeners weekly via 650 NPR stations.

“I like being in situations where people want to be there, and I’m not very good at telling people, you know, ‘sit down,’ or ‘get in there,’” Gross says on Finding Your Roots. “I’m not that person, and when I was 21, I was super not that person.”