New video from the fire in the Longwood section of the Bronx Tuesday morning reveals the moments the explosion rocked the neighborhood.

The explosion happened a little before 11 a.m. Neighbors in the area say they felt and heard a loud boom before the fire and smoke. The building collapsed less than five minutes after the explosion happened. The FDNY spent over an hour getting water on the fire, which gutted the building and also destroyed the buildings on either side of it.

MORE: Massive fire causes partial building collapse; 77-year-old woman dead

Police body camera footage shows officers rushing in. Martha Dagbasta, 77, was killed. She was found lying next to her sister by officials. Seven people were injured in total, including five police officers.

Crews were back on site Wednesday working to build a fence around the buildings. While fire officials originally said three buildings were destroyed, that number is now up to four. A source told News 12 they'd be using an excavator out front to tear them down.

The Red Cross says it worked with 20 people from 10 units to find them temporary housing in hotels.

Officials say the full cause of the incident is still under investigation, but foul play has been ruled out. Council Member Rafael Salamanca also confirmed that there was a 911 call about the smell of gas just before the explosion. He said Con Edison was running tests today.