Edward Herrmann’s last project was narrating a three part, six-hour documentary on cancer for PBS, Cancer: The Emperor Of All Maladies, debuting March 30.

Herrmann collapsed during his first day working on the narration, director Barak Goodman told TV critics at the TCA Winter Press Tour. The actor was able to work that day, but he explained to the docu’s team that he had terminal brain cancer. “We decided we could go forward,” Goodman said. “He was confident he could do this, and he felt it [was appropriate to] be his final project.” While Herrmann was receiving some new forms of treatment, he and his wife, “I think were reconciled to the fact he wasn’t going to make it,” Goodman said. “He did a magnificent job. … I can’t tell you how hard he pushed to get this right.”

Filmmaker Ken Burns, who had worked often with Herrmann, called the actor’s death on New Year’s Eve “incredibly sad.”

Asked why he did not direct this docu, which is being marketed as a “Ken Burns Presents” three-parter, Burns said he’d been too busy. He ticked off projects he had going at the time the book on which the cancer docu is based was brought to him: Dust Bowl, Central Park Five, Gettysburg Address, Prohibition, etc. Instead, he and frequent collaborator Geoffrey Ward “identified” Goodman to direct and worked with him on the script, Burns said. He corrected one TV critic who called it the first instance of Burns “presenting” something he had not directed, saying he did similarly in the mid-’90s, with The West.

Journalists were surprised to see Terrence Howard at the Q&A; he appeared in a video that opened the session, talking about his mother’s cancer. Howard has been a presence at this tour, what with his starring in Fox’s new Wayward Pines and Empire – and taking questions at the latter’s Q&A about the various women who’ve accused him of assault over the years. Burns said they’d hired an outside production company to shoot vignettes with people whose lives were affected by cancer, which would be used with “ever-increasing frequency” in the days leading up to Cancer’s debut on PBS.

“What you saw in the Terrence Howard clip is one of the vignettes finished more than a year ago,” Burns said, insisting Howard was not chosen “in anticipation of Empire … but of a good story well told, and honorably told.”