Polish Radio's CEO Agnieszka Kamińska emphasised the symbolism of the date.
Exactly 82 years ago, on September 7, 1939, then Warsaw Mayor Stefan Starzyński called on residents to defend the Polish capital against the German assault and work for the benefit of the whole community.
"Polish Radio staff took up this challenge," Kamińska said.
"With enormous dedication and devotion, at a risk to their own lives and health, they made sure Polish Radio continued its broadcasts for as long as September 30," she added.
In doing so, Polish Radio staff "sustained the spirits of the fighting Varsovians as well as the whole nation," Kamińska also said.
Photo: Cezary Piwowarski/Polish Radio
Their heroism also shines through in the fact that they managed to preserve steel-made gramophone records from the time, those at the ceremony were told.
Containing speeches by Starzyński and then-Foreign Minister Józef Beck, among other recordings, the 93 original discs have been put on UNESCO's "Memory of the World" list, Polish Radio’s IAR news agency reported.
Kamińska revealed the Polish public radio broadcaster was preparing a special re-issue of these records.
The new commemorative plaque bears the names of several dozen of Polish Radio workers from September 1939, a list that may be extended in the future,.
In addition to the plaque, an exhibition opened at Polish Radio's Warsaw headquarters on Tuesday, showcasing the people, places and events that defined the broadcaster's work in September 1939.
Source: IAR, polskieradio.pl