A teen who was celebrating the end of his exams with friends in a park later suffered a fatal asthma attack that his family says was triggered by a severe reaction to pollen.

Joe Dale, who was 16 at the time of the tragic June 2017 incident, had been diagnosed with the respiratory condition when he was 5, but had only had one asthma attack at age 12, SWNS reported.

When Dale returned to his friend’s house after the park, he had an asthma attack and lost consciousness despite using an inhaler moments before, according to the news outlet. He was rushed to the hospital and spent six days on life support before his parents took him off it.

Pollen is a common trigger for allergic asthma, which can cause the passage in the airways of the lungs to become inflamed and swollen, resulting in coughing, wheezing and other asthma symptoms. Dale’s parents said they want to share their tragedy in hopes of spreading awareness about the potential dangers of common triggers for asthma sufferers.