A explosion at a Bronx apartment building set off a massive fire and led to a partial building collapse on Tuesday. FDNY confirmed a major emergency response and said four civilians and three police officers were injured. Their conditions were not immediately clear. Eyewitnesses told News 4 they heard at least two explosions, followed by flames. Onlookers at first thought it was snowing, until they realized it was ash from the fire coming down instead. 00:00 Intro 00:25 Live Look 01:29 Witness Describes Explosions 02:20 Good Samaritan Helps Residents