ALLAHABAD, India — Anxious relatives searched for missing family members in northern India on Monday during one of the world's largest religious gatherings, unsure if their loved ones were caught in a stampede that killed 37 people or had simply gotten lost among the tens of millions of pilgrims.

People thronged to the main hospital in Allahabad to see if their relatives were among 37 dead and 39 people injured in Sunday evening's stampede at the city's train station. Tens of thousands of people were in the station waiting to board a train when railway officials announced a last-minute change in the platform, triggering the chaos.

An estimated 30 million Hindus took a dip Sunday at the Sangam — the confluence of the Ganges, the Yamuna and the mythical Saraswati rivers — as part of the 55-day Kumbh Mela, or Pitcher Festival. Sunday was one of the holiest days to bathe.