An explosion in a Detroit apartment injured seven adults and six children early Monday morning, authorities said. The blast ripped through a 12-unit building on the city’s west side around 4 a.m., sparking an immediate response from firefighters and medical personnel. “It sounded like a bomb,” building resident Ashley Ridner told local NBC affiliate WDIV. Ridner, her boyfriend and their 5-year-old son were all rescued by first responders. The two-story building was divided by a firewall, officials said. The explosion occurred on a side with eight units, while the side with four units suffered minimal damage. All residents were evacuated. When firefighters reached the scene, they saw people in the windows “kind of hanging off ready to jump,” Detroit Fire Commissioner Chuck Simms said, noting the people were instead rescued by firefighters. “Without their fast response and fast thinking this could have been a lot worse.” The cause of the explosion remained under investigation into Monday afternoon. Initial signs indicated a gas leak, and local utility provider DTE Energy turned off the gas at the request of police, according to the Detroit Free Press. The explosion triggered an emergency alert to cellphones across Detroit at around 6 a.m., waking many residents, according to local Fox affiliate WJBK. Officials said the alert was only intended for the zip code where the explosion occurred and was mistakenly sent to a wider area. ...read more read less