The Paris landmark also had a message for the broader French public: Stay home.
Lights spelled out “Merci," French for ‘Thank you,” and “Stay at home" in English on Friday night along with the tower's famous sparkling illuminations.
The display of solidarity that started at 8 p.m. (1900 GMT) coincided with the moment when citizens in lockdown across France have been cheering and applauding from their windows and balconies in support of doctors and nurses.
Paris Mayor Anne Hidalgo said the light show will take place every evening on the 324-meter-tall tower.
French hospitals recorded nearly 2,000 virus-related deaths as of Friday, a figure that doesn’t include COVID-19 cases elsewhere. Health workers are straining to treat an ever-increasing number of patients, including nearly 3,800 in intensive care.
For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia, and death.
In neighboring Switzerland, authorities also are lighting up one of the nation’s landmarks, the Matterhorn.
Nightly from sundown until 11 p.m., light artist Gerry Hofstetter is splashing the Alpine peak with words and images of encouragement and inspiration.
Images on the snow-capped summit have shown a heart, the Swiss flag, “Hope” and "#stayhome."