The Mathayomsuksa 5 level student, whose name was withheld by police, misstepped after he tried selfie photography from the fourth floor of the department.
His friends told police that they came to the department in order to make selfie photography from the deck floor after many friends who went there told about the panorama view there.
They sneaked onto the deck floor via fire escape stairs to the top.
The victim was asked to take selfie of the group, but he misstepped and fell to the ground.
He was admitted to Phyathai Sriracha hospital where his condition was critical.