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.

People were trampled as pilgrims at the Maha Kumbh Mela, one of the world’s biggest gatherings, gathered where the Ganges and Yamuna Rivers meet, officials said.

For many Hindu pilgrims, bathing at the festival where three holy rivers meet is the spiritual journey of a lifetime. But as millions descended on this northeast Indian tent city, was it a disaster waiting to happen?