<p>Officials determined a deadly New York City fire that killed 12 on Thursday, December 28, was caused by a child playing with a stove burner. The New York City Fire Department posted video on Friday showing the inside of the building after the fire.</p><p>The mother of the child who started the fire fled from the building with her two children but failed to close the door behind her, officials said</a>. The stairwell acted as a chimney, spreading the fire quickly, officials said</a>.</p><p>Firefighters distributed fire education materials</a> on Friday, and officials distributed on social media</a> information about the Juvenile Fire-Setters Intervention Program. Credit: FDNY via Storyful</p><br />