(NBC News) – Drones lit up the night sky in Madrid, Spain, to remember COVID-19 victims.

Forty programmed drones with multi-colored LED lights danced an aerial ballet, forming different shapes and letters. The figure included a heart and two people.

The messages expressed hope for the end of the pandemic and thanks for the people fighting it.

The location of the performance remained a secret until it took place to avoid crowds forming.

Madrid City Hall launched the drones Friday night.

Spain has been one of the worst-hit countries from COVID-19, with over 248,000 total cases, according to the Johns Hopkins University & Medicine Coronavirus Resource Center.