The New Jalpaiguri police started an unnatural death case, but no complaint was lodged.(Representational)

A class 9 student died and his batchmate was seriously injured after falling through an open window of their classroom on the second floor of the school building at Fulbari, police said.

Principal T Rajni Prasad said, the incident occurred during lunch break on Monday when the students, Rishab Arya and Hrithik Kumar Singh, pushed each other, lost control and tumbled out of the window.

"Unfortunately, the window from which they fell had no grilles. I had no information that the grilles were broken three days ago and had been removed," the principal said.

Both the students were taken to a private hospital immediately, but Rishab Arya, who hailed from Bihar, was declared "brought dead" by the doctors, the principal said.

Hrithik Kumar Singh sustained a fracture on his left hand, his father said.

The police has seized the hard disk of the CCTV camera system installed in the school premises. They also spoke to security guards who were on duty, a police officer said.

West Bengal Tourism minister Gautam Deb met the school authorities and families of both the students on Monday.

Describing the incident as "unfortunate", he said "We will try to find out how could such an incident can take place in a school."

The New Jalpaiguri police started an unnatural death case, though no complaint was lodged.

The co-educational secondary school is affiliated to the CBSE.