From Wikipedia (adapted)
April 28: Workers’ Memorial Day, World Day for Safety and Health at Work
Workers’ Memorial Day takes place annually around the world on April 28, an international day of remembrance and action for workers killed, disabled, injured, or made unwell by their work.
During 2001 the ILO, part of the United Nations, recognized Workers’ Memorial Day and declared it World Day for Safety and Health at Work. In 2002 the ILO announced that April 28 should be an official day in the United Nations system. It is concerned about safe work and awareness of the dimensions and consequences of work-related accidents and diseases. The aim is to place occupational safety and health (OSH) on the agendas and to support national efforts for the improvement of OSH systems and programs in line with international labor standards.