The 15-year-old has been charged with murder, assault, and arson after the fire on Evergreen Avenue in Soundview last week.
A 27-year-old man was pronounced dead at the scene. Two other people were hurt.
City inspectors say the first and second floors of the building had been illegally converted into eight different rooms.
ALSO READ | NYPD addresses backlash over viral video of officers taken after Drake concert at the Apollo
NYPD responds to backlash over video taken after Drake concert
----------
* More Bronx news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
Submit a tip or story idea to Eyewitness News
Have a breaking news tip or an idea for a story we should cover? Send it to Eyewitness News using the form below. If attaching a video or photo, terms of use apply.