People left candles, flowers and messages near the entrance of Los Olivos metro station in memory of the victims of the collapsed elevated track of Metro Line 12 in Mexico City. /CFP

The tragedy killed at least 25 with at least 79 injured, the deadliest incident in decades for the city's metro system. /CFP

The elevated track collapsed on May 3, 2021, when a train was traveling on it, causing it to crash and plunge to the road. /CFP

The Mexico City's metro Line 12, also known as the "Golden Line," spans 25.1 kilometers and features 20 stations. It was boasted as one of the most costly and ambitious public works projects in Mexican history when inaugurated in October 2012. /CFP