Police are investigating the death, on Monday afternoon, of a 55-year-old physical education teacher at St Mary's College.
Police said officers of the Port of Spain Division were called to the school at around 5 pm after one of the teachers, Joel Garcia, was found unresponsive in a room on the western side of the school.
Officers were told that Garcia complained of feeling unwell and had had chest pains, earlier.
An ambulance was called in, and EMTs tried to resuscitate Garcia. They took him to the Port of Spain General Hospital where he was declared dead.
No marks of violence were found on Garcia's body.
Officers of the Port of Spain Division are continuing enquiries.