In the 1980s, the Post faced the most serious blow to its credibility during Bradlee's watch and it all came to light due to an award.

In early 1981, Janet Cooke confessed to Bradlee that the Pulitzer Prize-winning piece she had written about an 8-year-old heroin user was completely fabricated. Jimmy, the compelling, forlorn child of the drug culture, was a concoction of Cooke's imagination and for Bradlee, the phantom character was an editor's worst nightmare.

"It is tragedy that someone as talented and promising as Janet Cooke, with everything going for her, felt that she had to falsify the facts," said Bradlee at the time. "The credibility of a newspaper is its most precious asset, and it depends almost entirely on the integrity of its reporters. When that integrity is questioned and found wanting, the wounds are grievous, and there is nothing to do but come clean with our readers, apologize to the Advisory Board of the Pulitzer Prizes, and begin immediately on the uphill task of regaining our credibility. This we are doing."

It was an episode that Bradlee said he still deeply internalizes, recalling the artwork and narrative of the original story in detail.

"Her description of this child was so vivid, and the description of the child's mother and the mother's boyfriend -- you know, they had names," Bradlee recalled in his conversation with Jim Lehrer. "They were described. There was an illustration to that story I can still see today, a very haunting of this child."

The incident shook the editor's world to its foundations.

"We didn't know her as well as we thought we knew her," Bradlee said.

Read More about the Janet Cooke story