The Royal Castle is seen lit up in blue along with the Swietokrzyski bridge in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)

The facade of the Royal Castle is lit up in blue in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)

The Royal Castle, lit up in blue, is seen from the Swietokrzyski bridge in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)

The facade of the Royal Castle is lit up in blue in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)

The facade of the Royal Castle is lit up in blue in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)

The Royal Castle, lit up in blue, is seen from the Swietokrzyski bridge in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)

The Royal Castle, lit up in blue, is seen from the Swietokrzyski bridge in Warsaw, Poland on April 7, 2020. The facade of the Royal Castle is to be lit in blue for two evenings in a row to support healthcare professionals fighting for lives amid the spread of the coronavirus. The Royal Castle, a building whose history is deeply intertwined with the history of the nation, wants to show it's solidarity in the face of an overwhelming crisis. (Photo by Jaap Arriens/Xinhua)