The Gwinnett County medical examiner's office says a Dacula High School student who died after collapsing at school Tuesday died of a pulmonary embolism.

The student, identified as 18-year-old Christopher Smith, may have injured his ankle a couple of weeks ago causing a blood clot that broke off and went to his lungs, according to autopsy results released to WSB's Sandra Parrish.

Students and faculty at Dacula High School have been trying to come to grips with the sudden death of the 11^th grade student.

Gwinnett County Schools spokeswoman Sloan Roach says Smith fell ill during a third period gym class.

“A teacher who was there responded as did the school’s nurse who is (a registered nurse),” she said.

The young man was transported to a local hospital by ambulance. A short time later, school officials received word that the he had died.

Parents learned of the tragedy in a letter posted on the school's website  http://www.daculahs.org/home.html.

“When we received word of this student’s passing, we shared this sad news with our teachers and staff,” wrote Principal Donald Nutt. “We also met with classmates of the student and also have had our counselors and other support team members available at our school….”

Nutt’s letter concluded, “I know your thoughts and prayers will be with this student’s family, our students, our faculty and our school as a whole as we cope with this loss.”