Day of Mourning
Every year more people are killed at work than in wars. Most don't die of mystery ailments, or in tragic "accidents". They die because an employer decided their safety just wasn't that important a priority. The Day of Mourning commemorates those workers.
The Day of Mourning is held on April 28th every year; all over the world, workers and their representatives conduct events, demonstrations, vigils and a whole host of other activities to mark the day, which is also intended to serve as a rallying cry to "remember the dead, but fight like hell for the living".