An 11-year-old boy who died on New Year’s Day after visiting family members in Brooklyn may have had a fatal reaction to fish proteins released into the air while his relatives cooked.

The sixth grader, Cameron Jean-Pierre, had asthma and was allergic to fish and peanuts, his father, Steven Jean-Pierre, said on Thursday in an interview with WABC.

They had been visiting Cameron’s grandmother in the Canarsie neighborhood of Brooklyn, where one of his relatives was making fish, and Cameron had an asthma attack, Mr. Jean-Pierre said.

Cameron’s father treated his son with a nebulizer, a device they had used many times in the past to deliver medicine to the boy’s lungs.