A vermilion dot on the forehead is one of India’s most widely accepted Hindu cultural insignias. But at the festival, where millions are flocking to pray and bathe at the confluence of India’s holy rivers, it morphs into a major display of Hinduism in various forms and designs.

The Hindu festival that turned deadly in northern India on Wednesday is a religious gathering with deep spiritual meaning for devotees who come by the millions to take a cleansing dip in waters they consider sacred.