On April 8th, 2016, the sunrise in Medellín was more cloudy than normal. The city had completed three weeks on alert for a critical air quality level and had registered a new high of contamination. The gray clouds did not discourage a group of citizens from carrying out an urban intervention in Plaza Botero – one of the most emblematic touristic sites of Medellín – to start a discussion in the streets about the air conditions that two and a half million people breathe every day. The sculptures by artist Fernando Botero were covered with masks to protect them from the dangerous levels of contamination in the city centre in Medellín.