Officials say six people were injured after a Newark Housing Authority apartment building collapsed on Friday.

Multiple residents told News 12 New Jersey the collapse was due to a gas explosion.

The explosion was caught on a video.

PSE&G turned off the gas during the investigation, but the cause of the damage had yet to be determined as of Saturday night.

Residents also told News 12 New Jersey the Newark Housing Authority was out earlier in day knocking on doors to check on them and making sure there was no smell of gas.

The Public Works Department began debris removal on Saturday.

Crews gutted the entire left side of the building at the Stephen Crane apartments.

Mayor Ras Baraka gave a quick press conference on Friday night and said the city and the Red Cross are helping impacted residents.

The Department of Public Safety reported that 31 people, including 28 adults and three children, were relocated.

Out of those six people injured, they said one is being treated for serious burns.

News 12 New Jersey spoke with Toby Marmorino, who said he knows that man that was injured. He said he actually saw him coming out of the building right after he suffered severe burns.

"Extremely loud explosion, felt the vibration, car alarms went off and everything," Marmorino said. "He made it out, I don’t know how, I think he may have gotten blown into the apartment next door, I'm not sure, because he walked out of the next-door neighbors' door, skin peeling off of him. He got burned up pretty bad."