Thanks to a forbidden communications tactic, your ears can now travel through time.

Back in the late 1930’s, CBS Radio affiliate KIRO in Seattle had a problem. Each night, the CBS network broadcast the day’s news live from New York, scheduled for maximum impact to listeners in the Eastern Time Zone. But in Seattle, three hours behind, many listeners were still at work or on their way home and would miss the day’s major stories. So KIRO violated CBS policy and engaged in a tactic known as “timeshifting” the radio broadcast. They recorded the news from New York as it was being broadcast, sat on it for three hours, and then aired it on a schedule that suited their west coast audience.

This presented KIRO a big challenge: how to record hours and hours of content in an era when digital formats didn’t exist. The only available solution was to use 16-inch lacquer discs which could hold a lot of material, but which unfortunately could not be reused. Day after day, the station created a mountain of used discs which they piled in the corner. And once the station was full of old discs, they should have been just thrown them all away. But someone made the odd decision to pack them all up and move them offsite; for several years, all of KIRO’s time-delayed news broadcasts were saved and stored at the station’s transmission station on Vashon Island.

Skip forward to 1957. A University of Washington professor named Milo Ryan discovered the archive and immediately realized its value. Together with KIRO station manager Loren Stone, he arranged to have the discs moved to the university, where engineers from two on-campus radio stations painstakingly sorted and recorded the material onto reel-to-reel tape. In 1963, Professor Ryan published a full catalog of the material in the University of Washington Press. Then, in 2002, the original discs were moved to the National Archive and Records Administration (NARA) in Maryland for permanent preservation.

And so today we have something completely unauthorized, unexpected, unplanned and utterly invaluable: a nearly complete archive of CBS radio news from the World War II years. Edward R. Murrow reporting from London. The Battle of Britain. Normandy. VE Day. The Atomic Bomb. VJ Day. All captured as they were reported, minute by minute, day by day. It’s the only such archive available to historians, or to you and me.

And it only exists because of a surreptitious bit of corporate rule-breaking.

Says NARA librarian Sam Brylawski, “KIRO should get a gold star for ‘inadvertent archiving.’ That wasn’t their intention, but thank God they did it.”