At least 8 people injured in Chicago residential building blast

Chicago [US], September 21 : At least eight people were injured after an explosion ripped through a residential building in Chicago on Tuesday (local time), according to local fire department authorities.
Chicago Fire Department confirmed the explosion at 9:45 am (local time) and tweeted pictures which showed that the top floor of the four-story brick apartment building on the city's West Side almost completely destroyed by the blast.
The department said that the blast occurred near Washington Boulevard and Central Avenue.
"Background on explosion. This is a four-story apartment building. With 35 units. Investigation underway into cause by CFD OFI. Assisted by ATF and CPD. Looking at 4th Floor as possible source," Chicago Fire Department said in a tweet.
ABC News reported that three of those injured are in a critical condition.
Fire officials said that a building adjacent to the site of the explosion was being evacuated.
Deputy Fire Commissioner Marc Ferman told reporters during a midday briefing that first responders have completed primary and secondary searches of the building after the explosion.
"Right now we feel like we're confident we got everybody out," Ferman said. The fourth floor of the building had collapsed and was "compromised," he said, as per reports.
Two of the victims are female, while the other six are male, according to the fire department. One victim was in a building across the street from the explosion when it happened, Ferman said. Ten ambulances and 135 first responders were called to the scene, Ferman said.

Meanwhile, videos have surfaced on social media, showing debris strewn across the sidewalk, streets and several cars and windows were blown out of the building.
According to CBS News the apartment building had failed annual inspections repeatedly over the last 12 years, and received citations in 2017 and 2018 for "failing to repair or replace defective or out of service smoke detectors and operate continuously."