The 50 students filed into a Bronx auditorium, chatting excitedly and snapping selfies while fixing the colorful sashes adorned with flags from 17 countries, forming a mosaic of nationalities: Dominican Republic, Honduras, Gambia, Senegal, Mali.

Spanish and French filled the air as teary-eyed parents held balloons and watched their children, all of whom had migrated to the United States about four years ago, many not knowing a word of English back then.

Out of the hundreds of graduations this month at New York City public schools, the one held by the Ellis Preparatory Academy was different. The Bronx high school of about 250 students is one of the few dedicated exclusively to recently arrived immigrants, many of whom may be undocumented or have tenuous legal status.

But before they could get their diplomas, the school’s principal felt compelled to interrupt the celebratory mood: She had to pay tribute to a Venezuelan student who was sitting in an immigration detention center about 275 miles away in Pennsylvania.

“One of our own was taken,” Norma Vega, the principal who founded the school in 2008, said on Tuesday. “We want to make sure that no matter where we are, no matter where we go, that we always keep him in front and center.”