"We found that people had fallen on top of each other, one person over another," Abhishek, who survived the fatal stampede in India's eastern city of Kolkata, told CGTN Stringer.

The tragedy unfolded at a religious celebration on Saturday over India's festive season. Worshippers had gathered in thousands when a sudden downpour triggered panic.

Abhishek recounts how 1,500 people rushed inside a temporary pavilion with the capacity to hold 500 to escape the rain.

"The people inside the pandal did not come out because they were trying to avoid getting wet in the rain," Abhishek said.

The death toll has since risen to 19. Twenty-five others are receiving hospital treatment and one is said to be in critical condition.