Gabriel Comeau, a 13-year-old air cadet from Saint John who died on Tuesday, was attending a three-week basic fitness and sports camp at 14 Wing Greenwood in Nova Scotia when he collapsed, say military officials.

Lt.-Col. John Cater, the commanding officer of the Greenwood Cadet Training Centre, said Wednesday the teen was taking a day off on Tuesday when he came out of his room around 1 p.m. and reported he felt sick.

"He did lose consciousness and was unresponsive," Cater said.

The boy was rushed to a hospital in Kentville, N.S., around 3 p.m. and later died.

Rear-Admiral Jennifer Bennett, from the Chief Reserves and Cadets, released a statement Wednesday evening, saying she is "deeply saddened" to hear of Comeau's death.

"I have been told by those close to him that Gabriel loved being a part of Air Cadets and he was so happy when he finally reached the age of 12 that he could sign up and be with his two older brothers to share the experience of Air Cadets together," she said.

Flags at 14 Wing Greenwood flew half-mast on Wednesday. (Elizabeth Chiu/CBC)

In an email to parents at École Samuel-De-Champlain in Saint John, where Comeau was a student, school officials said Wednesday they were all hit hard by the loss. The building will be open to the community on Thursday from 7 p.m. to 9 p.m. to provide an informal gathering place for those needing it, the email said.

The school said funeral details would be announced at a later date.

"We are working with the family to ensure they have all of the assistance we can provide for them and ensure their well-being," Cater said.

Cater would not disclose whether the teen had any medical conditions. He said that information would have been shared with medical staff when the camp started.

Military police investigating

"On arrival, every cadet is screened by our medical staff and if they do have an allergy that requires an EpiPen, they are advised and counselled on the fact that they have to keep it with them at all times in order to access it when they need it," he said.

Cater said since the teenager died suddenly, the Canadian Forces National Investigation Service — the investigative arm of the military police — will look into the matter.

There's no word on the cause of the boy's death.

The base made grief counsellors available, Cater said.

"It is business as usual, but we did make it clear to all the cadets and all of the staff that the training is secondary and the needs of the cadets and the staff are paramount and they trump all other considerations," he said.

Instructors reminded cadets to carry personal medications, drink water and take rests.

About 1,000 cadets go through the summer program. They range from age 12 to 18.

Bennett said Comeau's death was being felt "across our entire institution."

"We can only imagine the tremendous sadness of his family and close friends," she said, adding that their focus is on supporting the cadet's family, fellow cadets and instructors.